title: Can't get SHA1 from flutter project because of "The option setting 'android.enableR8=false' is deprecated"
body: <p>I want to get SHA1 with this comment <code>gradlew signingReport</code> in my android folder. But I can't.</p>
  <p>my gradle version is 4.0.2.
  I tried to delete the <code>android.enableR8=true</code> from the gradle.propertie file, But nothing changed!</p>
  <p>Result of <code>gradlew signingReport --scan</code></p>
  <pre><code>&gt; Configure project :app
  WARNING: The option setting 'android.enableR8=false' is deprecated.
  It will be removed in version 5.0 of the Android Gradle plugin.
  You will no longer be able to disable R8
  
  &gt; Configure project :file_picker
  WARNING: The option setting 'android.enableR8=true' is deprecated.
  It will be removed in version 5.0 of the Android Gradle plugin.
  You will no longer be able to disable R8
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Task 'singingReport' not found in root project 'android'. Some candidates are: 'signingReport'.
  
  * Try:
  Run gradlew tasks to get a list of available tasks. Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log
  output. Run with --scan to get full insights.
  
  * Get more help at https://help.gradle.org
  
  Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
  Use '--warning-mode all' to show the individual deprecation warnings.
  See https://docs.gradle.org/6.1.1/userguide/command_line_interface.html#sec:command_line_warnings
  
  BUILD FAILED in 55s
  
  Publishing a build scan to scans.gradle.com requires accepting the Gradle Terms of Service defined at https://gradle.com/terms-of-service. Do you accept these terms? [yes, no] y
  Please enter 'yes' or 'no': yes
  
  Gradle Terms of Service accepted.
  
  Publishing build scan...
  </code></pre>
  <p>Result of <code>gradlew singingReport --scan</code>:</p>
  <pre><code>Initialized native services in: C:\Users\Ali Azad\.gradle\native
  The client will now receive all logging from the daemon (pid: 6348). The daemon log file: C:\Users\Ali Azad\.gradle\daemon\6.1.1\daemon-6348.out.log
  Starting 7th build in daemon [uptime: 1 hrs 22 mins 57.548 secs, performance: 99%, GC rate: 0.00/s, heap usage: 9% of 1.1 GB]
  Using 2 worker leases.
  Starting Build
  Settings evaluated using settings file 'D:\projects\Flutter Projects\mobile-app\android\settings.gradle'.
  Projects loaded. Root project using build file 'D:\projects\Flutter Projects\mobile-app\android\build.gradle'.
  Included projects: [root project 'android', project ':app', project ':file_picker', project ':firebase_auth', project ':firebase_core', project ':flutter_plugin_android_lifecycle', project ':flutter_splash_screen', project ':google_maps_flutter', project ':google_sign_in', project ':image_cropper', project ':image_picker', project ':location', project ':shared_preferences', project ':webview_flutter']
  
  &gt; Configure project :
  Evaluating root project 'android' using build file 'D:\projects\Flutter Projects\mobile-app\android\build.gradle'.
  
  &gt; Configure project :app
  Evaluating project ':app' using build file 'D:\projects\Flutter Projects\mobile-app\android\app\build.gradle'.
  WARNING: The option setting 'android.enableR8=false' is deprecated.
  It will be removed in version 5.0 of the Android Gradle plugin.
  You will no longer be able to disable R8
  Creating configuration androidTestUtil
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  Configuring Java sources compilation with source level 1.8 and target level 1.8.
  
  &gt; Configure project :file_picker
  Evaluating project ':file_picker' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\file_picker-2.0.13\android\build.gradle'.
  WARNING: The option setting 'android.enableR8=true' is deprecated.
  It will be removed in version 5.0 of the Android Gradle plugin.
  You will no longer be able to disable R8
  Creating configuration androidTestUtil
  
  &gt; Configure project :firebase_auth
  Evaluating project ':firebase_auth' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\firebase_auth-0.18.3\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :firebase_core
  Evaluating project ':firebase_core' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\firebase_core-0.5.2\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :flutter_plugin_android_lifecycle
  Evaluating project ':flutter_plugin_android_lifecycle' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\flutter_plugin_android_lifecycle-1.0.11\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :flutter_splash_screen
  Evaluating project ':flutter_splash_screen' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\flutter_splash_screen-0.1.0\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :google_maps_flutter
  Evaluating project ':google_maps_flutter' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\google_maps_flutter-1.0.6\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :google_sign_in
  Evaluating project ':google_sign_in' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\google_sign_in-4.5.6\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :image_cropper
  Evaluating project ':image_cropper' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\image_cropper-1.3.1\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :image_picker
  Evaluating project ':image_picker' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\image_picker-0.6.7+14\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :location
  Evaluating project ':location' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\location-2.5.4\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :shared_preferences
  Evaluating project ':shared_preferences' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\shared_preferences-0.5.12+4\android\build.gradle'.
  Creating configuration androidTestUtil
  
  &gt; Configure project :webview_flutter
  Evaluating project ':webview_flutter' using build file 'D:\Learning\flutter\flutter_sdk\.pub-cache\hosted\pub.dartlang.org\webview_flutter-1.0.7\android\build.gradle'.
  Creating configuration androidTestUtil
  All projects evaluated.
  Analytics other plugin to proto: Unknown plugin type FlutterPlugin expected enum FLUTTERPLUGIN
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  Configuring Java sources compilation with source level 1.7 and target level 1.7.
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Task 'singingReport' not found in root project 'android'. Some candidates are: 'signingReport'.
  
  * Try:
  Run gradlew tasks to get a list of available tasks. Run with --stacktrace option to get the stack trace. Run with --debug option to get more log output. Run with --scan to get full insights.
  
  * Get more help at https://help.gradle.org
  
  Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
  Use '--warning-mode all' to show the individual deprecation warnings.
  See https://docs.gradle.org/6.1.1/userguide/command_line_interface.html#sec:command_line_warnings
  
  BUILD FAILED in 10s
  </code></pre>