9762 Fall back to a fully qualified path to libapp.so if the library can not be loaded by name (cla: yes)

9767 Un-deprecated FlutterViewController’s binaryMessenger. (cla: yes)

9769 Document //flutter/shell/common/engine. (cla: yes)

9772 fix objcdoc generation (cla: yes)

9781 SendPlatformMessage allow null message value (cla: yes)

9789 fix ColorFilter.matrix constness (cla: yes)

9791 Roll Wuffs and buildroot (cla: yes)

9792 Update flutter_web to latest (cla: yes)

9793 Fix typo in PlaceholderAlignment docs (cla: yes)

9797 Remove breaking asserts (cla: yes)