Merge "Forces a back region for sandbox even if gesture nav is disabled." into sc-dev am: e0a94aa750 am: c229b84d64

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14513829

Change-Id: I0c72b8d77310b8b100c6a3a14b4f1f8c966c7f9c