Merge "Explicit Nullbility in Launcher (Part 2)" into tm-qpr-dev am: 775b0d21 am: ff8f09b5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/19679564



Change-Id: I569d5e6fd9ebbcb31266c6683c129481ee3c2144
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>