Merge "Remove unused string resources" am: 9f7902f0 am: 882a8796 am: 3382c178 am: 1be49409

Original change: https://android-review.googlesource.com/c/platform/packages/apps/DocumentsUI/+/1507583



Change-Id: I927c485d459c1bf1eabb92ee21ecd3d9d5728d17
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>