41206 Cherry-picks (cla: yes, engine)

41207 Bump version of just package:multicast_dns (cla: yes, team)

41211 Update AUTHORS (cla: yes, framework, waiting for tree to go green)

41213 Revert engine roll (cla: yes, engine)

41220 Add an ActivateAction to controls that use InkWell. (cla: yes, f: material design, framework, severe: API break, team)

41222 Copy archived js part files out of dart_tool directory (cla: yes, tool, ☸ platform-web)

41224 fix flutter error report correct local widget (a: error message, cla: yes, framework, from: study, team, tool)