title: Create Android Library on Flutter project
body: <p>I am trying to create an android library on top of flutter project for distribution. I have developed an app using flutter, but I want to wrap it in an Android library.  I keep getting error <code>Transform output file /Users/Dev/Documents/projects/LibExample/testlib/build/intermediates/flutter/flutter-x86.jar does not exist.</code> I have read search almost everything online, but nothing so far. </p>
  
  <p>The <code>LibExample</code> is my sample app to use the library while <code>testlib</code> is the Android library. In the <code>testlib</code> I have set up my <code>build.graddle</code> to locate the <code>flutter.sdk</code>. I have also specified the flutter source location. Each time I <code>sync</code> the gradle file, I get the error /Users/Dev/Documents/projects/LibExample/testlib/build/intermediates/flutter/flutter-x86.jar does not exist.
  `</p>
  
  <p>Here is the output for <code>flutter doctor -v</code>.</p>
  
  <pre><code>flutter doctor -v
  [✓] Flutter (Channel beta, v0.5.2-pre.1, on Mac OS X 10.13.6 17G65, locale en-US)
      • Flutter version 0.5.2-pre.1 at /Users/Dev/Downloads/flutter
      • Framework revision 142e2f41ba (9 weeks ago), 2018-09-03 12:50:53 +0100
      • Engine revision 1ed25ca7b7
      • Dart version 2.0.0-dev.58.0.flutter-f981f09760
  
  [✓] Android toolchain - develop for Android devices (Android SDK 28.0.3)
      • Android SDK at /Users/Dev/Library/Android/sdk
      • Android NDK location not configured (optional; useful for native profiling support)
      • Platform android-28, build-tools 28.0.3
      • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
      • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
      • All Android licenses accepted.
  
  [✓] iOS toolchain - develop for iOS devices (Xcode 10.1)
      • Xcode at /Applications/Xcode.app/Contents/Developer
      • Xcode 10.1, Build version 10B61
      • ios-deploy 1.9.2
      • CocoaPods version 1.5.3
  
  [✓] Android Studio (version 3.2)
      • Android Studio at /Applications/Android Studio.app/Contents
      • Flutter plugin version 29.1.1
      • Dart plugin version 181.5656
      • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
  
  [!] VS Code (version 1.28.0)
      • VS Code at /Applications/Visual Studio Code.app/Contents
      • Flutter extension not installed; install from
        https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter
  
  [✓] Connected devices (1 available)
      • Android SDK built for x86 • emulator-5554 • android-x86 • Android 5.1.1 (API 22) (emulator)
  
  ! Doctor found issues in 1 category.
  </code></pre>