74862 Migrate automated_tests to null-safety (cla: yes, team, waiting for tree to go green)

74865 Add canRun override to FakeProcessManager (cla: yes, team, tool)

74866 Add fixes for nullOk changes (a: null-safety, cla: yes, cp: 1.26, cp: 1.26 completed, f: cupertino, f: material design, framework, team, waiting for tree to go green)

74869 Revert “Remove package image dependency” (cla: yes, team, tool)

74874 Update packages (cla: yes, team, tool, waiting for tree to go green)

74885 Unpin mysteriously pinned packages (cla: yes, team, tool, waiting for tree to go green)