title: Error - Gradle sync failed : ASCII - flutter after adding firebase
body: <p><a href="https://i.stack.imgur.com/NaBrC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NaBrC.png" alt="enter image description here"></a>When I create my app it shows a red underline app-level build.gradle but while I debug my app is still running and the I add firebase to my app after generating SHA key and add JSON file in app folder it shows an error -
  Here is my app-level build.gradle shows error in line 24 -</p>
  
  <pre><code>def localProperties = new Properties()
  def localPropertiesFile = rootProject.file('local.properties')
  if (localPropertiesFile.exists()) {
      localPropertiesFile.withReader('UTF-8') { reader -&gt;
          localProperties.load(reader)
      }
  }
  
  def flutterRoot = localProperties.getProperty('flutter.sdk')
  if (flutterRoot == null) {
      throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
  }
  
  def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
  if (flutterVersionCode == null) {
      flutterVersionCode = '1'
  }
  
  def flutterVersionName = localProperties.getProperty('flutter.versionName')
  if (flutterVersionName == null) {
      flutterVersionName = '1.0'
  }
  //line 24
  apply plugin: 'com.android.application'
  apply plugin: 'kotlin-android'
  apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
  
  android {
      compileSdkVersion 28
  
      sourceSets {
          main.java.srcDirs += 'src/main/kotlin'
      }
  
      lintOptions {
          disable 'InvalidPackage'
      }
  
      defaultConfig {
          // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
          applicationId "mdhv.co.clone_skype"
          minSdkVersion 16
          targetSdkVersion 28
          versionCode flutterVersionCode.toInteger()
          versionName flutterVersionName
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      }
  
      buildTypes {
          release {
              // TODO: Add your own signing config for the release build.
              // Signing with the debug keys for now, so `flutter run --release` works.
              signingConfig signingConfigs.debug
          }
      }
  }
  
  flutter {
      source '../..'
  }
  
  dependencies {
      implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'com.android.support.test:runner:1.0.2'
      androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
  }
  classpath 'com.google.gms:google-services:4.3.2'
  </code></pre>
  
  <p>Flutter doctor run properly</p>