70277 Improve the behavior of DropdownButton.disabledHint (cla: yes, f: material design, framework, waiting for tree to go green)

70311 [Material] Add selection control themes (cla: yes, f: material design, framework, waiting for tree to go green)

70319 Revert usages of the binding’s platformDispatcher to use window instead (a: accessibility, a: tests, cla: yes, framework)

70321 Add autofill troubleshooting tips to autofillHints documentation (cla: yes, framework, waiting for tree to go green)

70327 [flutter_releases] Flutter 1.22.4 framework cherrypicks (a: tests, cla: yes, d: examples, engine, f: cupertino, f: material design, framework, team, tool)