Merge "Show back and IME switcher for gesture nav (1/2)" into sc-v2-dev am: a102bd896f am: 38356b77e0

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15069670

Change-Id: Ifd4c73cfad3cee249669a0ffd1b930b451d96f3e