Merge "Renamin TaskbarContainerView to TaskbarDragLayer" into sc-dev am: 2f0595e76e am: 12829aee27 am: d106111de3

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

Change-Id: I427f8efcc65d884d89211565f96af6fdc4b4ff36