Merge "Prevent exfiltration of system files via avatar picker." into tm-dev am: 5489aa365f am: 33a08e907c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19754655

Change-Id: If8ac10c7073bf7db345118010591da611ee82394
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>