Merge "Prevent exfiltration of system files via avatar picker." into sc-dev am: 43e0f944cb am: f76ea6006a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19748987

Change-Id: I1b6518355105946b55ae7c6255ec89f80585bc50
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>