Add server support for DNS-over-TLS
By default, Android Pie devices automatically upgrade to DNS over TLS if a network's DNS server supports it. We could support this feature in routers. The only issues is, that user should securte valid certificate, so Android device will accept it.
https://dnsprivacy.org/wiki/display/DP/Using+Unbound+as+a+DNS+Privacy+server
and
https://dnsprivacy.org/wiki/display/DP/Using+Knot-resolver+as+a+DNS+Privacy+server