[Predictive Back] Refactor setClipChildrenOnViewTree/restoreClipChildrenOnViewTree to support clipToPadding

Bug: 325930715
Test: Added unit test
Flag: aconfig com.android.launcher3.enable_predictive_back_gesture TEAMFOOD
Change-Id: I509546ac4ee1fa851cf0648d365a5348362267cc
5 files changed