Merge "Add split support for 3P launcher" into sc-v2-dev am: 42cbdee25c am: 809cef23a5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/16416933

Change-Id: I6305941be879350ab192cf3be0fa0a4edf8ffe99