OMS: Add config_signature policy handling am: 0f942f99ca am: 98f8388042 am: 1dd9fa3689

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1453997

Change-Id: I6eb6791bc9ab2e8ee8b50404e5d2e9bb9eb77e9e