Merge "Added debug menu option for testing secondary display." into tm-qpr-dev am: 06b1d8c114 am: d8a2537ec0

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/19701174

Change-Id: Idb221d4f7bc7ff4827d57804d308c79e9ada942d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>