Merge "[OneSearch] Add a clear function in the plugin to clear cache and memory." into sc-v2-dev am: 3118d24449

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15749048

Change-Id: I56c12dd0f9e3ec2289d447e69a7733b6ea8102fd