Merge "Add utilities for network validation testing" am: ff15197c34

Original change: https://android-review.googlesource.com/c/platform/cts/+/1364518

Change-Id: Ia6f360509892910706d5f92aa98a9243feb9fd98
tree: 025e128883a46990432264c243af41847d157542
  1. tests/