Merge "Fix NPE when converting final screen to empty screen." into sc-qpr1-dev am: 70dd01be85 am: 46db057249 am: 2a3c1321f8

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15583988

Change-Id: Ia2286f2f63dce45f0ac3199260ddefa50e7541f1