8820 remove legacy build deps (cla: yes)

8821 Remove asserts and add BuildConfig (cla: yes)

8823 Add font features (such as tabular numbers) as an option in text styles (cla: yes)

8824 Guard Android logs (cla: yes)

8825 Remove static leaks (cla: yes)

8826 New Plugin API PR1: Introduces PluginRegistry and FlutterPlugin, adds support for plugin registration to FlutterEngine. (cla: yes)

8830 Cause crash in FlutterJNI if invoked on non-main thread in debug mode (#31263). (cla: yes)

8833 Default the animated frame cache to 0 when unset (cla: yes)

8837 Only cache required frames (cla: yes)