Revert "Remove FakeDns from NetworkStack tests."

This reverts commit 156efb1732449991ef4834b8f3492995d2377d24.

Reason for revert: <Potential culprit for b/368232541  - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.>

Change-Id: I11bb97748e33359cb5b97f583421a6c8be86239c
3 files changed