Merge "Load widget preview images before adding the rows to the adapter" into sc-dev am: dd19a24769 am: 23cbe6ef6b

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

Change-Id: I82cc0a723913df9a7fb83fe036e13facc34dd5e4