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: I3df1615746d3012d15321ded344c930651795225