Merge "Update taskbar drag and drop treatment" into sc-v2-dev am: da86c0e64d am: ccb17341b1

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/16134100

Change-Id: I78de1b27ca39cc050b7dd9884e5312e7f12cbbc5