Currently, it looks like private DNS server resolution uses
OneAddressPerFamilyNetwork and only returns one server address.
It should return all addresses. Use async dns api for this.
Bug: 123435238
Test: atest NetworkStacktests
Change-Id: I2b7e184d9b9800a83b55dceb73af69085668748c
(cherry picked from commit 40c5295cee)
Merged-In: I2b7e184d9b9800a83b55dceb73af69085668748c
Merged-In: I9f50da3c8c2e3b12b29bc8844291e4bf1559cd1f