Validate package name passed to setApplicationRestrictions. am: 8c2c7b41 am: 9abccf15

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



Change-Id: I4761e364fe4a2c9b4311b5ada9c711e8171a8e66
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>