Merge "Replace WallpaperData File fields with methods" into udc-qpr-dev am: c18e0fe3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23766386



Change-Id: I4da20a9df8c19eeb4e9479e4cd1ca1d20d5d2e25
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>