Merge "Remove unused string resources" am: 9f7902f0 am: 882a8796

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



Change-Id: I261e49f998a2072623035d3e929c3aaba1c0de37
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>