85306 Add space before curly parentheses. (a: tests, team, tool, framework, f: material design, cla: yes, f: cupertino, waiting for tree to go green)

85351 Removed ButtonBar from flutter_gallery (team, f: material design, cla: yes, waiting for tree to go green)

85358 Replace uses of ButtonBar in doc/samples with Overflowbar (framework, f: material design, cla: yes, waiting for tree to go green)

85370 Audit hashCode overrides outside of packages/flutter (a: tests, team, tool, framework, f: material design, a: accessibility, cla: yes, waiting for tree to go green)

85412 Update flutter doc references to conform to new lookup code restrictions (a: tests, framework, f: material design, cla: yes, f: cupertino, waiting for tree to go green)