
This property would previously have been used by
ad9e4fef45/shell/platform/android/io/flutter/app/FlutterActivityDelegate.java (L59C31-L59C58)
but isn't used by the new `FlutterActivityAndFragmentDelegate`. It's also recommended to be removed by the original v1->v2 updating guide: https://github.com/flutter/flutter/blob/master/docs/platforms/android/Upgrading-pre-1.12-Android-projects.md