[ST03] Add test dns server for integration tests

This is re-upload of aosp/1390056, CL that fixes test is separated
in a follow-up CL that submit at the same time.

Bug: 139774492
Test: atest DnsAnswerProviderTest TestDnsServerTest
Change-Id: Ia72975f3044f009ebb0f4564a527830268a4a157
3 files changed
tree: 5900cc2acca5c73439bc0680431d76087e96f785
  1. staticlibs/