19344 Implement onDisplayPlatformView (cla: yes, platform-android, waiting for tree to go green)

19346 Roll Dart SDK from 7fc61e77e225 to 871f0ee31eb0 (4 revisions) (cla: yes, waiting for tree to go green)

19347 Roll Fuchsia Linux SDK from _d0dW… to Y_dK2… (cla: yes, waiting for tree to go green)

19348 Roll Fuchsia Mac SDK from l3tHO… to SuveI… (cla: yes, waiting for tree to go green)

19349 Roll Fuchsia Linux SDK from Y_dK2… to lgSTC… (cla: yes, waiting for tree to go green)