Merge "Expose AppOpsManager#OPSTR_ACTIVATE_PLATFORM_VPN as system API" am: 01bec3bb2b am: b8eb5b0ee1 am: b892146fb4 am: d667289cc6

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

Change-Id: I5b315cd95cd0be59debb75caf9678845b284b666