Merge "Remove APP_SEARCH_IMPROVEMENTS" into sc-dev am: 9450883e74 am: 75987bddd3

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

Change-Id: I61e80fffbfe59c76558d2e62b3630e0d1b558396