Use AggressiveConfiguration as the default configuration in IOS

webrtc/sdk/objc/Framework/Classes/RTCConfiguration.mm

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 23 matching lines @@
 @synthesize keyType = _keyType;
 @synthesize iceCandidatePoolSize = _iceCandidatePoolSize;
 @synthesize shouldPruneTurnPorts = _shouldPruneTurnPorts;
 @synthesize shouldPresumeWritableWhenFullyRelayed =
     _shouldPresumeWritableWhenFullyRelayed;
 
 - (instancetype)init {
   if (self = [super init]) {
     _iceServers = [NSMutableArray array];
     // Copy defaults.
-    webrtc::PeerConnectionInterface::RTCConfiguration config;
+    webrtc::PeerConnectionInterface::RTCConfiguration config(true);
     _iceTransportPolicy =
         [[self class] transportPolicyForTransportsType:config.type];
     _bundlePolicy =
         [[self class] bundlePolicyForNativePolicy:config.bundle_policy];
     _rtcpMuxPolicy =
         [[self class] rtcpMuxPolicyForNativePolicy:config.rtcp_mux_policy];
     _tcpCandidatePolicy = [[self class] tcpCandidatePolicyForNativePolicy:
         config.tcp_candidate_policy];
     _candidateNetworkPolicy = [[self class]
         candidateNetworkPolicyForNativePolicy:config.candidate_network_policy];
@@ skipping 31 matching lines @@
       _iceCandidatePoolSize,
       _shouldPruneTurnPorts,
       _shouldPresumeWritableWhenFullyRelayed];
 }
 
 #pragma mark - Private
 
 - (webrtc::PeerConnectionInterface::RTCConfiguration *)
     createNativeConfiguration {
   std::unique_ptr<webrtc::PeerConnectionInterface::RTCConfiguration>
-      nativeConfig(new webrtc::PeerConnectionInterface::RTCConfiguration());
+      nativeConfig(new webrtc::PeerConnectionInterface::RTCConfiguration(true));
 
   for (RTCIceServer *iceServer in _iceServers) {
     nativeConfig->servers.push_back(iceServer.nativeServer);
   }
   nativeConfig->type =
       [[self class] nativeTransportsTypeForTransportPolicy:_iceTransportPolicy];
   nativeConfig->bundle_policy =
       [[self class] nativeBundlePolicyForPolicy:_bundlePolicy];
   nativeConfig->rtcp_mux_policy =
       [[self class] nativeRtcpMuxPolicyForPolicy:_rtcpMuxPolicy];
@@ skipping 228 matching lines @@
     (RTCEncryptionKeyType)keyType {
   switch (keyType) {
     case RTCEncryptionKeyTypeRSA:
       return rtc::KT_RSA;
     case RTCEncryptionKeyTypeECDSA:
       return rtc::KT_ECDSA;
   }
 }
 
 @end