Merge "Remove unused volume strings." into udc-dev am: 1a5b3cbc

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22212097



Change-Id: I61c127aea46d953c5a0bce1d10574c66d23a3b1f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>