Build Flutter App

First of all, add flutter_automation package to your dev dependencies section in pubspec.yaml. 

If flutter packages get doesn't run automatically, run flutter packages get from terminal to get the newly added dependency. 

flutter pub pub run flutter_automation --android-sign

flow the steps

flutter build apk

or

flutter build appbundle --target-platform android-arm,android-arm64,android-x64

Notes:
In case you get error "Gradle does not have execution permission", run the next command

chmod a+rx android/gradlew