Merge "Make sure we start new activity only in UI thread." into tm-qpr-dev am:...

Merge "Make sure we start new activity only in UI thread." into tm-qpr-dev am: fd2471b9 am: 52f3078c

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/21484427



Change-Id: Idd5019c6f5f95219ac13cc70b2e4842dbac70392
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>