Merge "Renamin TaskbarContainerView to TaskbarDragLayer" into sc-dev am: 2f0595e76e am: 1b72c0ea35 am: 7796916a88

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14680570

Change-Id: I4dc7a3fc2ee26cfdaa802fed600ef9850ef87319