Merge "Make MockVpn more realistic and easier to use." am: 0dd10f43c7

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1501814

Change-Id: I6584e231913841dc218573dc586429cd720621a3
tree: df6c2768a07034c93583e64ddcb33d52743af1ff
  1. core/
  2. services/
  3. tests/