Merge "Predictive back: widget to all apps" into tm-qpr-dev am: e73db2a011 am: c5a715f531

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/20968630

Change-Id: I06791cb598cb1be27a285ae98812650fe3ceffec
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>