MediaTransportTests should use audio-only peer connection.

Currently (and this has to change), media transport is created two times if audio&video is used (even if bundling is enabled).
The second time it's destroyed really quickly (but given lack of 'Connect' method, the connection has already started).

This change adds a TODO and modifies existing tests to prevent creation of 2 media transports.



Bug: webrtc:9719
Change-Id: I872e98dcd10685beb0326d501f0e0abf36c0fdfc
Reviewed-on: https://webrtc-review.googlesource.com/c/110887
Reviewed-by: Anton Sukhanov <sukhanov@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Commit-Queue: Peter Slatala <psla@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25660}
diff --git a/pc/jseptransportcontroller.cc b/pc/jseptransportcontroller.cc
index cb99686..9457ed7 100644
--- a/pc/jseptransportcontroller.cc
+++ b/pc/jseptransportcontroller.cc
@@ -762,6 +762,10 @@
   // BaseChannel/SctpTransport change the RtpTransport/DtlsTransport first,
   // then destroy the cricket::JsepTransport.
   if (SetTransportForMid(content_info.name, jsep_transport)) {
+    // TODO(bugs.webrtc.org/9719) For media transport this is far from ideal,
+    // because it means that we first create media transport and start
+    // connecting it, and then we destroy it. We will need to address it before
+    // video path is enabled.
     MaybeDestroyJsepTransport(content_info.name);
     return true;
   }