Validate package name passed to setApplicationRestrictions. am: 8c2c7b4164 am: 9abccf1549 am: a5d9003562

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19754637

Change-Id: I58c1df5bcf78dae5185586a714153553b785ee0c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>