68642 Sound null safety for framework and flutter_test (a: tests, cla: yes, d: examples, f: cupertino, f: material design, framework, team)

68644 Fix overscroll edge case that puts NestedScrollViews out of sync (cla: yes, f: scrolling, framework, severe: regression, waiting for tree to go green)

68645 Migrate flutter_localizations to null safety. (a: internationalization, cla: yes, f: cupertino, f: material design, framework, team)

68646 Remove the defaults for textBaseline (cla: yes, framework, waiting for tree to go green)

68654 Driver vm service (a: tests, cla: yes, framework, t: flutter driver, team, waiting for tree to go green)

68661 Fix null safety error in inspector service extensions taking a variable number of args. (cla: yes, framework)