28277 [android] Fix black and blank screen issues on the platform view page. (platform-android, cla: yes, needs tests)

28278 Roll Skia from e12730470004 to 0f36d11c1dcf (13 revisions) (cla: yes, waiting for tree to go green)

28279 Roll Dart SDK from abecc4bc4521 to 72f462ed2d34 (6 revisions) (cla: yes, waiting for tree to go green)

28280 Roll Skia from 0f36d11c1dcf to 6f90c702e6c8 (4 revisions) (cla: yes, waiting for tree to go green)

28281 Eliminate unnecessary null check in fixture (cla: yes, needs tests, embedder)