These are sent if the device receives IPv6 Router Advertisements with DNS server configuration options. Currently, nothing listens to them; in a future change we will use them as IPv6 DNS servers. [Cherry-pick of 416740ad4d9132005a71dc0883334e852235a18a] Bug: 9180552 Change-Id: I05000c0cd3867a68ab390102e8470b6912a9d3aa