19649 Manual Roll of Dart dfdc7e45c5…06cb010247 (cla: yes)

19650 Manual Skia roll to c91db040ad18b9cc3236e342e9acca020eaafd10 (cla: yes)

19652 Move platform specific information to PlatformConfiguration class (cla: yes, waiting for tree to go green)

19653 1.20.0-7.1.pre engine CPs (platform-android)

19657 Manual Roll of Dart 707c6404f9…dfdc7e45c5 (cla: yes)

19658 Moved to RMSE for image comparison to account for slight variations in golden image tests (cla: yes)