title: Cannot Build Flutter App in Release Mode but works fine in debug mode
body: <p>Below is the build error which flutter is giving , I don't know what i am doing wrong, my project is android.x supported still getting error, when i run it in debug mode it works perfect but as i build signed apk for release mode it starts giving me this error which is now really annoying me more than a day i am stuck in this </p>
  
  <pre><code>FAILURE: Build failed with an exception.
  
  
  
  * What went wrong:
  
  Execution failed for task ':thumbnails:verifyReleaseResources'.
  
  &gt; A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
  
     &gt; Android resource linking failed
  
       C:\Users\Raja ahmed\.gradle\caches\transforms-2\files-2.1\c1da7862c7abb8e426855a3f78caf221\core-1.0.0\res\values\values.xml:57:5-88:25: AAPT: error: resource android:attr/fontVariationSettings not found.
  
  
  
       C:\Users\Raja ahmed\.gradle\caches\transforms-2\files-2.1\c1da7862c7abb8e426855a3f78caf221\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 455h 48m 24s
  Running Gradle task 'assembleRelease'...                           55.9s
  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 firebase_admob...
  Running Gradle task 'assembleAarRelease'...
  The plugin firebase_admob could not be built due to the issue above.
  </code></pre>
  
  <p>pubspec.yaml</p>
  
  <pre><code>  splashscreen: ^1.2.0
    firebase_admob: ^0.9.3+1
    cupertino_icons: ^0.1.2
    share: ^0.6.3+5
    url_launcher: ^5.4.1
    permission_handler: ^4.0.0
    flutter_staggered_grid_view: ^0.3.0
    path_provider: ^1.5.1
    image_gallery_saver: ^1.2.2
    flutter_html: ^0.11.1
    flutter_fab_dialer: ^0.1.1
    thumbnails: ^1.0.1
    chewie: ^0.9.8+1
    video_player: ^0.10.5+1
  
  
  
     assets:
   - assets/loading.gif
   - assets/video_loader.gif
   - assets/bg1.jpg
  </code></pre>
  
  <p>default config in build.grade</p>
  
  <pre><code> defaultConfig {
          // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
          applicationId "com.rajaonceagain.statussaver"
          minSdkVersion 21
          targetSdkVersion 28
          versionCode flutterVersionCode.toInteger()
          versionName flutterVersionName
          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
          multiDexEnabled true
      }
  </code></pre>
  
  <p>its been now more than a day i am looking for this solution. I just update visual studio code nothing else , the day before i made a signed apk for release mode for other project and it worked perfect but dont know why today its causing this problem</p>