Merge "Rely on presense of divider target to determine split screen state" into sc-v2-dev am: 46e0999612

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15662829

Change-Id: I34a9d1ba5b81e1858781338b192cedb6b0abde08