41338 Fix ReorderableListView’s use of child keys (#41334) (cla: yes, f: material design, framework)

41342 Revert engine rolls (cla: yes, engine)

41347 Fix timing issues in initialization of web resident runner (cla: yes, tool)

41355 fix bad indentations(mainly around collection literals) (cla: yes, f: cupertino, f: material design, framework, team, tool)

41378 Fix erroneous comments referring to blobs snapshots. (cla: yes, team)

41384 [flutter_tools] Report iOS mDNS lookup failures to analytics (cla: yes, tool)

41386 Serve every html file under web (cla: yes, tool)