19418 Roll Skia from 1c62a7b034c0 to 2d7cf46c815b (1 revision) (cla: yes, waiting for tree to go green)

19419 Remove linux_host_release_tests. (cla: yes)

19420 Roll Skia from 2d7cf46c815b to 746460e25a1e (7 revisions) (cla: yes, waiting for tree to go green)

19421 Update scenario UI screenshoots (cla: yes, platform-android)

19423 Rename Sk* classes to Ck* in preparation for @JS migration (cla: yes)

19426 Implement mutator stack on Android hybrid composition platform view (cla: yes, platform-android, waiting for tree to go green)