81700 Roll Engine from 3e578c6e0d77 to 578449f10fde (23 revisions) (cla: yes, waiting for tree to go green, will affect goldens)

82712 [flutter_test/integration_test] added setSurfaceSize test coverage (a: tests, framework, cla: yes, will affect goldens, integration_test)

83379 Add ability to specify Image widget opacity as an animation (framework, cla: yes, waiting for tree to go green, will affect goldens)

84840 fix _owner nullability in routers.dart (framework, cla: yes, f: routes, will affect goldens, a: null-safety)

85736 Remove “unnecessary” imports. (waiting for customer response, tool, framework, f: material design, a: accessibility, cla: yes, waiting for tree to go green, will affect goldens)