Merge "Remove APP_SEARCH_IMPROVEMENTS" into sc-dev am: 9450883e74 am: d4ccaa1de6 am: 0f0c0ff8e2

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14829362

Change-Id: Icc088413e635c8d91b272c1f38c4838c49995d0f