79297 Add scrollbar tests for simultaneous scroll/drag (a: tests, cla: yes, f: cupertino, f: material design, f: scrolling, framework, waiting for tree to go green)

79302 Reland Make LogicalKeyboardKey.keyLabel a getter and better #79100 (a: tests, cla: yes, framework, team, waiting for tree to go green)

79310 Always write full timeline before summary (a: tests, cla: yes, framework, team)

79407 Rolls isKeyboardKey engine change with fix (a: accessibility, a: tests, cla: yes, engine, framework, waiting for tree to go green)

79486 [flutter_releases] Flutter Stable 2.0.4 Framework Cherrypicks (a: tests, cla: yes, engine, f: cupertino, f: material design, framework, team, tool)