Merge "Center nav bar vertically" into tm-dev am: a8c73beb am: 5911b9e6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18717447



Change-Id: I0a2999c63f39ae1902e88d8318965fed9a647553
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>