Merge "Remove APP_SEARCH_IMPROVEMENTS" into sc-dev am: 9450883e74 am: 75987bddd3 am: ea6b3db51d

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

Change-Id: Iaee30ea22e6b388b6ea3cea6c68d7cd0ca1c5d1b