title: Flutter - The plugin firebase_core could not be built
body: <p>I am building my flutter release build for Android and firebase_core plugin is crashing during build. Previously everything used to work fine but I made a fresh install of windows, Android studio and downloaded latest flutter sdk. Now this error with firebase_core plugin is showing up. Here are my logs</p>
  
  <pre><code>D:\AndroidProjets\my_app&gt;flutter build apk --split-per-abi
  Running Gradle task 'assembleRelease'...
  Note: D:\flutter\.pub-cache\hosted\pub.dartlang.org\firebase_messaging-6.0.9\android\src\main\java\io\flutter\plugins\firebasemessaging\FirebaseMessagingPlugin.java uses or overrides a deprecated API.
  Note: Recompile with -Xlint:deprecation for details.
  D:\flutter\.pub-cache\hosted\pub.dartlang.org\shared_preferences-0.5.6+2\android\src\main\java\io\flutter\plugins\sharedpreferences\SharedPreferencesPlugin.java:25: warning: [deprecation] getFlutterEngine() in FlutterPluginBinding h
  as been deprecated
      setupChannel(binding.getFlutterEngine().getDartExecutor(), binding.getApplicationContext());
                          ^
  1 warning
  Note: Some input files use or override a deprecated API.
  Note: Recompile with -Xlint:deprecation for details.
  Removed unused resources: Binary resource data reduced from 658KB to 635KB: Removed 3%
  Removed unused resources: Binary resource data reduced from 658KB to 635KB: Removed 3%
  Removed unused resources: Binary resource data reduced from 658KB to 635KB: Removed 3%
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':clipboard_manager:verifyReleaseResources'.
  &gt; A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
     &gt; Android resource linking failed
       C:\Users\.gradle\caches\transforms-2\files-2.1\c5476b279721c45ae2c1305903c71386\core-1.0.0\res\values\values.xml:57:5-88:25: AAPT: error: resource android:attr/fontVariationSettings not found.
  
       C:\Users\.gradle\caches\transforms-2\files-2.1\c5476b279721c45ae2c1305903c71386\core-1.0.0\res\values\values.xml:57:5-88:25: AAPT: error: resource android:attr/ttcIndex not found.
  
  
  * Try:
  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
  
  BUILD FAILED in 4m 3s
  Running Gradle task 'assembleRelease'...
  Running Gradle task 'assembleRelease'... Done                     244.7s (!)
  The built failed likely due to AndroidX incompatibilities in a plugin. The tool is about to try using Jetfier to solve the incompatibility.
  Building plugin admob_flutter...
  Running Gradle task 'assembleAarRelease'...
  Running Gradle task 'assembleAarRelease'... Done                   22.1s
  √ Built build\app\outputs\repo.
  Building plugin clipboard_manager...
  Running Gradle task 'assembleAarRelease'...
  Running Gradle task 'assembleAarRelease'... Done                   20.3s
  √ Built build\app\outputs\repo.
  Building plugin firebase_analytics...
  Running Gradle task 'assembleAarRelease'...
  Running Gradle task 'assembleAarRelease'... Done                   22.5s
  √ Built build\app\outputs\repo.
  Building plugin firebase_core...
  The plugin firebase_core could not be built due to the issue above.
  Running Gradle task 'assembleAarRelease'... 
  </code></pre>
  
  <p>And for the build.gradle</p>
  
  <pre><code>android {
      compileSdkVersion 29
  
      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 ""
          minSdkVersion 19
          targetSdkVersion 29
          versionCode flutterVersionCode.toInteger()
          versionName flutterVersionName
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      }
  
      signingConfigs {
          release {
              keyAlias keystoreProperties['keyAlias']
              keyPassword keystoreProperties['keyPassword']
              storeFile file(keystoreProperties['storeFile'])
              storePassword keystoreProperties['storePassword']
              v1SigningEnabled true
              v2SigningEnabled true
          }
      }
      buildTypes {
          release {
              signingConfig signingConfigs.release
  
              minifyEnabled true
              useProguard true
              shrinkResources true
  
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
  
          }
      }
  
      aaptOptions {
          cruncherEnabled = false
      }
  }
  </code></pre>
  
  <p>And finally my pubspec.yaml dependencies</p>
  
  <pre><code>cupertino_icons: ^0.1.3
    shared_preferences: ^0.5.6+2
    get_it: ^3.1.0
    http: ^0.12.0+4
    url_launcher: ^5.4.2
    flutter_staggered_animations: ^0.1.2
    cached_network_image: ^2.0.0
    intl: ^0.16.1
    clipboard_manager: ^0.0.4
    flutter_svg: ^0.17.1
    photo_view: ^0.9.2
    rxdart: ^0.23.1
    firebase_core: ^0.4.4
    firebase_analytics: ^5.0.11
    firebase_crashlytics: ^0.1.3
    firebase_messaging: ^6.0.9
    flutter_local_notifications: ^1.1.6
    admob_flutter: ^0.3.4
    auto_direction: ^0.0.4+1
    rate_my_app: ^0.6.0
    flutter_rating_bar: ^3.0.1+1
    flutter_linkify: ^3.1.0
  </code></pre>