Merge "Use the LayoutManager as the source of truth for visible positions" into sc-dev am: 5cc44eb73e am: 9cbd6cdf14

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14800536

Change-Id: Iffc733be5c0651e6786a10b2653cffdc4fde545c