Merge "Respect CentralSurfaces being optional in NavBarHelper" into tm-qpr-dev am: 8415396e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19517483



Change-Id: Ie3aacaec9903574941f297c1e5fdadd32f70ba31
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>