PlatformNavBar backgroundColor does nothing on Android

[StepanMynarik]

PlatformNavBar backgroundColor does nothing on Android, but changing backgroundColor even on just one BottomNavigationBarItem changes the PlatformNavBar background color everywhere (of all buttons at the same time).

Flutter: 1.17.3
flutter_platform_widgets: 0.50.1

EDIT: MaterialNavBarData backgroundColor also doesn't change anything on Android. So far only the BottomNavigationBarItem backgroundColor property works. And even that works in mysterious ways, as explained above.

[StepanMynarik]

I see now, it is a fault of Flutter weird behavior, see: flutter/flutter#13642