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: I010f2ef1d374d668155f0d6c960ff7f9001f149d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>