39912 Revert “Build flutter_gallery with bitcode” (cla: yes, d: examples, team, team: gallery)

39917 Fix new prefer_const_constructors after analyzer fix. (a: tests, cla: yes, d: examples, framework, team, team: gallery)

39919 CupertinoDatePicker & CupertinoTimerPicker dark mode (cla: yes, f: cupertino, framework, severe: API break, will affect goldens)

39924 Adds DartPad option to the DartDoc snippet generator. (cla: yes, f: material design, framework, team)

39927 Make CupertinoDynamicColor.resolve return null when given a null color (cla: yes, f: cupertino, framework)

39932 update packages –force upgrade (cla: yes, team)