Change the gating of surfacing candidates on ICE transport type change

from a field trial to RTCConfiguration.

The test coverage is also expanded for the underlying feature.

Bug: None
Change-Id: Ic9c1362867e4a956c5453be7a9355083b6a442f5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/138980
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Alex Glaznev <glaznev@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Amit Hilbuch <amithi@webrtc.org>
Commit-Queue: Qingsi Wang <qingsi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28143}

sdk/android/api/org/webrtc/PeerConnection.java

@@ -450,6 +450,7 @@ public class PeerConnection {
     public int iceCandidatePoolSize;
     public boolean pruneTurnPorts;
     public boolean presumeWritableWhenFullyRelayed;
+    public boolean surfaceIceCandidatesOnIceTransportTypeChanged;
     // The following fields define intervals in milliseconds at which ICE
     // connectivity checks are sent.
     //
@@ -552,6 +553,7 @@ public class PeerConnection {
       iceCandidatePoolSize = 0;
       pruneTurnPorts = false;
       presumeWritableWhenFullyRelayed = false;
+      surfaceIceCandidatesOnIceTransportTypeChanged = false;
       iceCheckIntervalStrongConnectivityMs = null;
       iceCheckIntervalWeakConnectivityMs = null;
       iceCheckMinInterval = null;
@@ -658,6 +660,11 @@ public class PeerConnection {
       return presumeWritableWhenFullyRelayed;
     }
 
+    @CalledByNative("RTCConfiguration")
+    boolean getSurfaceIceCandidatesOnIceTransportTypeChanged() {
+      return surfaceIceCandidatesOnIceTransportTypeChanged;
+    }
+
     @Nullable
     @CalledByNative("RTCConfiguration")
     Integer getIceCheckIntervalStrongConnectivity() {