63430 Updated old button references in dev/integration_tests/flutter_gallery leave_behind_demo (f: material design, team)

63431 Revert “Add native stacktrace field for PlatformException” (framework)

63432 Updated old button references in dev/integration_tests/flutter_gallery … transformation_demo (team)

63433 Remove more timeouts (tool, waiting for tree to go green)

63434 add FrameTimingSummarizer (a: tests, framework, team, waiting for tree to go green)

63436 Trivial typo fixes to snippets documentation (cla: yes, team, waiting for tree to go green)

63438 More restoration documentation (cla: yes, d: api docs, d: examples, documentation, framework, team, waiting for tree to go green)