21314 Detect errors encoding method channel responses (cla: yes)

21315 Roll Dart SDK from c660a695266a to c61a0818e4bd (1 revision) (cla: yes, waiting for tree to go green)

21316 Add FlEventChannel (cla: yes, waiting for customer response)

21317 Roll Fuchsia Linux SDK from 2rXyLF0YK… to VgNGzw-DQ… (cla: yes, waiting for tree to go green)

21318 Roll Skia from 1a49a5334c36 to 7a1f241c0134 (4 revisions) (cla: yes, waiting for tree to go green)