Merge "Load widget preview images before adding the rows to the adapter" into sc-dev am: dd19a24769 am: 50820e1fb5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14965044

Change-Id: I027775c831c25b2828cd2e278b1fcc3a25efbe45