Merge "Add GroupedTaskView for gestures in staged split." into sc-v2-dev am: ca1d523734 am: 7afaf2731e

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15467633

Change-Id: If6bd74213f1da7a4a76e42fb4c5e44b36b14edf8