[Keyboard, Android] Modifier key_down can have 0 modifier, leading to crash #108124
Description
Internal issue b/238717013 reported a crash with the following log:
java.lang.AssertionError: Unexpected metaState 0 for key 0x200000102 during an ACTION_down event.
java.lang.AssertionError
at io.flutter.embedding.android.KeyEmbedderResponder.synchronizePressingKey(PG:12)
at io.flutter.embedding.android.KeyEmbedderResponder.handleEventImpl(PG:5)
at io.flutter.embedding.android.KeyEmbedderResponder.handleEvent(PG:1)
at io.flutter.embedding.android.KeyboardManager.handleEvent(PG:5)
at io.flutter.embedding.android.FlutterView.dispatchKeyEvent(PG:5)
which indicates that Android sent a modifier Shift Left key down with the Shift meta state as 0, causing crashes.