32521 Reland matrix check (cla: yes)

32527 Added ‘enabled’ property to the PopupMenuButton (cla: yes, f: material design, framework)

32528 Tapping a modal bottom sheet should not dismiss it by default (cla: yes, f: material design, framework)

32530 Add Actions to AppBar Sample Doc (cla: yes, d: api docs, f: material design, framework)

32535 Fix transforms for things with RenderPointerListeners (cla: yes)

32538 Adjust macOS build flow (cla: yes)

32620 Added ScrollController to TextField (cla: yes, f: cupertino, f: material design, f: scrolling, framework)

32638 Fix apidocs in _WidgetsAppState.basicLocaleListResolution (cla: yes, d: api docs, framework)