Merge "Adding finish signal to GestureNavContract." into tm-dev am: e633cca3bc

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/17610880

Change-Id: Iba26c5db2da7c3c0a5c70ce66ad92040fafc825c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>