11239 Remove dart entrypoint Intent parameter from FlutterActivity. (#38713)

12469 Started asserting the FlutterEngine is running before communicating over channels.

13403 Use DartExecutor.getBinaryMessenger in FlutterNativeView instead of deprecated send methods

Material

Material continues to a focus for the Flutter team.
In this release, we refreshed all Material widgets
with dark mode support. Also, we added support for
extending the height of the Scaffold’s body behind
the app bar, which was contributed by a community member!

36998 Added properties in DropdownButtonFormField to match DropdownButton

37962 Show search app bar theme

38583 Added InheritedTheme

38650 Allow independent theming of Persistent and Modal bottom sheets