7876 Revert “Remove unnecessary entry-point closurization.” (cla: yes)

7877 Revert “Shut down and restart the Dart VM as needed.” (cla: yes)

7878 Android embedding refactor pr5 add flutterengine impl (cla: yes)

7880 Test profile and release build and unit tests (cla: yes)

7882 Fix minor typos in accessibility action docs (cla: yes)

7883 Correct onAccessibilityFeaturesChanged docs (cla: yes)

7886 Revert “Android embedding refactor pr3 add remaining systemchannels” (cla: yes)

7891 Add accessibility semantics support to embedder (cla: yes)

7892 Android embedding refactor pr3 add remaining systemchannels (cla: yes)