Remove @WorkerThread annotation and Preconditions.assertWorkerThread check. am: f781ef81bf am: 82f0aaa1d5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/23566433

Change-Id: Iddd70c0bfbe2dae1653d5a9e4348f4751841705f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>