Merge "Cleanup WIDGETS_IN_LAUNCHER_PREVIEW." into udc-dev am: f8b4a4cc08

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/23245066

Change-Id: Ib4f3aea4b4ecdef1d2af7827c3433405568a1f6a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>