Merge "Update Back arrow colors" into udc-dev am: 60321d82

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23500449



Change-Id: Ie0e687377b34df006818a7cb53c2a9c747efc6f3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>