Merge "Explicit Nullbility in Launcher (Part 5)" into tm-qpr-dev am: 69c04c21

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/19976255



Change-Id: Id7d92e7b4c432e8caafb92b62956387bd0c1e42e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>