flutter项目打包Android apk的时候报错
报错内容：
ERROR: Missing classes detected while running R8. Please add the missing classes or apply additional keep rules that are generated in /Users/apple/Documents/code/mail/build/flutter_inappwebview_android/outputs/mapping/release/missing_rules.txt.
ERROR: R8: Missing class android.window.BackEvent (referenced from: void io.flutter.embedding.android.FlutterActivity.startBackGesture(android.window.BackEvent) and 3 other contexts)
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':flutter_inappwebview_android:minifyReleaseWithR8'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.R8Task$R8Runnable
> Compilation failed to complete
只有打包andorid的时候报错，运行到真机没有问题
请帮我解惑！
