48962 Update assert message for AnimatedContainer (cla: yes, framework)

48964 Roll engine 8c855dba98eb..c84fad959284 (4 commits) (autoroller: commit, cla: yes)

48975 [flutter_tools] Only remove ProcessUtils from injection (cla: yes, tool)

48976 Roll engine c84fad959284..e0fe8342889c (2 commits) (autoroller: commit, cla: yes)

48979 [flutter_tools] let experimental compiler support plugins (cla: yes, tool)

48982 Fix whitespace and commas in flutter_driver extension_test (a: tests, cla: yes, framework, t: flutter driver)