8538 Add null check in FLETextInputPlugin (cla: yes)

8540 Android Embedding PR29: Improve FlutterFragment construction API + engine config API. (cla: yes)

8541 Eliminate unused write to local (cla: yes)

8545 Revert “Change Rect internal representation from Float32List to Float64List (#8524)” (cla: yes)

8546 [font_collection] Add missing semicolon (cla: yes)

8548 Initialize OpacityLayer’s matrix to identity (#8467) (cla: yes)

8549 [fuchsia] Add flutter:: to scene_host.cc (cla: yes)

8550 Export extern constants in embedder.h (cla: yes)