Disable remote ICE candidate DNS lookups when the IceTransportPolicy is Relay or None

Bug: webrtc:11597
Change-Id: Id3884a2b5f0fc35880c7401c43ca25fee8346519
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/175960
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Qingsi Wang <qingsi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31389}
diff --git a/AUTHORS b/AUTHORS
index 499c340..90b6cb7 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -108,6 +108,7 @@
 Optical Tone Ltd <*@opticaltone.com>
 Pengutronix e.K. <*@pengutronix.de>
 RingCentral, Inc. <*@ringcentral.com>
+Signal Messenger, LLC <*@signal.org>
 Sinch AB <*@sinch.com>
 struktur AG <*@struktur.de>
 Telenor Digital AS <*@telenor.com>