Reland of Split iOS sdk in to separate targets

webrtc/sdk/objc/Framework/Classes/PeerConnection/RTCRtpParameters+Private.h

 /*
  *  Copyright 2016 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.
  */
 
 #import "WebRTC/RTCRtpParameters.h"
 
 #include "webrtc/api/rtpparameters.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
 @interface RTCRtpParameters ()
 
 /** Returns the equivalent native RtpParameters structure. */
 @property(nonatomic, readonly) webrtc::RtpParameters nativeParameters;
 
 /** Initialize the object with a native RtpParameters structure. */
 - (instancetype)initWithNativeParameters:
     (const webrtc::RtpParameters &)nativeParameters;
 
 @end
 
 NS_ASSUME_NONNULL_END