Merge "Expose AppOpsManager#OPSTR_ACTIVATE_PLATFORM_VPN as system API" am: 01bec3bb2b am: b8eb5b0ee1

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1484021

Change-Id: I280d5f807ee40838ab8abe865a3d272e58ce8cbb