Merge "Have a method to stop VPN and send event to VPN app" am: 4e08dae7

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2194337



Change-Id: I019295826411924d4753a2975dbe39b9d12372f7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>