Merge "Interface for WidgetPickerSearchPipeline." into sc-dev am: 94b622da80

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/13690209

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Icccc124ed4a5ef1b889a0fb24c277283b6b94548