86117 [flutter_conductor] migrate conductor to null-safety (team, framework, cla: yes, waiting for tree to go green)

86141 [flutter] tab navigation does not notify the focus scope node (framework, f: material design, cla: yes, waiting for tree to go green)

86171 Revert “Remove TextTheme deprecations” (framework, f: material design, cla: yes)

86188 Add a “troubleshooting” section to the AppBar API doc (framework, f: material design, cla: yes)

86198 AppBar.backwardsCompatibility now default false, deprecated (team, framework, f: material design, cla: yes)

86223 Null aware operator consistency (framework, f: material design, cla: yes, waiting for tree to go green)