Add a flag to actively reset the SRTP parameters

Add a new flag to RtcConfiguration. By setting that flag to true, the
SRTP parameters will be reset whenever the DTLS transports are reset
after every offer/answer negotiation.

The flag is added to Android and Objc wrapper as well.

This should only be used as a workaround for the linked bug, if the
application knows that the other party is affected (for instance,
using a version number).

TBR=sakal@webrtc.org, denicija@webrtc.org

Bug: chromium:835958
Change-Id: I6db025e1c69bf83e1b1908f7df4627430db9920c
Reviewed-on: https://webrtc-review.googlesource.com/83101
Commit-Queue: Zhi Huang <zhihuang@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23587}

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

@@ -45,6 +45,7 @@
 @synthesize iceRegatherIntervalRange = _iceRegatherIntervalRange;
 @synthesize sdpSemantics = _sdpSemantics;
 @synthesize turnCustomizer = _turnCustomizer;
+@synthesize activeResetSrtpParams = _activeResetSrtpParams;
 
 - (instancetype)init {
   // Copy defaults.
@@ -99,6 +100,7 @@
     }
     _sdpSemantics = [[self class] sdpSemanticsForNativeSdpSemantics:config.sdp_semantics];
     _turnCustomizer = config.turn_customizer;
+    _activeResetSrtpParams = config.active_reset_srtp_params;
   }
   return self;
 }
@@ -106,7 +108,7 @@
 - (NSString *)description {
   static NSString *formatString =
       @"RTCConfiguration: "
-      @"{\n%@\n%@\n%@\n%@\n%@\n%@\n%@\n%@\n%d\n%d\n%d\n%d\n%d\n%d\n%d\n%@\n%@\n%d\n%d\n}\n";
+      @"{\n%@\n%@\n%@\n%@\n%@\n%@\n%@\n%@\n%d\n%d\n%d\n%d\n%d\n%d\n%d\n%@\n%@\n%d\n%d\n%d\n}\n";
 
   return [NSString
       stringWithFormat:formatString,
@@ -128,7 +130,8 @@
                        _iceCheckMinInterval,
                        _iceRegatherIntervalRange,
                        _disableLinkLocalNetworks,
-                       _maxIPv6Networks];
+                       _maxIPv6Networks,
+                       _activeResetSrtpParams];
 }
 
 #pragma mark - Private
@@ -194,6 +197,7 @@
   if (_turnCustomizer) {
     nativeConfig->turn_customizer = _turnCustomizer;
   }
+  nativeConfig->active_reset_srtp_params = _activeResetSrtpParams ? true : false;
   return nativeConfig.release();
 }