Merge "Update nav bar buttons to spec." into tm-qpr-dev am: fc8606dadc

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/22211900

Change-Id: I420f528cb0558fb3b7716df9f0b26344c392c9e6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>