Merge "Adding finish signal to GestureNavContract." into tm-dev am: e633cca3bc am: 610df3623c

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

Change-Id: If6026fa6e90fa2b8c2991645bd4c4cdbe40a3093
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>