Merge "Moving slice loading on a background thread" into sc-dev am: b0bff050f2

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/13473795

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I025fc20f5fe66b8ab3c4cab57ca6fdbc2ad97f30