Fix AVFoundation framework import

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCCameraVideoCapturer.h

 /*
  *  Copyright 2017 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 <Foundation/Foundation.h>
+#import <AVFoundation/AVFoundation.h>
 
 #import <WebRTC/RTCMacros.h>
 #import <WebRTC/RTCVideoCapturer.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
 RTC_EXPORT
 // Camera capture that implements RTCVideoCapturer. Delivers frames to a RTCVideoCapturerDelegate
 // (usually RTCVideoSource).
 @interface RTCCameraVideoCapturer : RTCVideoCapturer
 
 // Capture session that is used for capturing. Valid from initialization to dealloc.
 @property(readonly, nonatomic) AVCaptureSession *captureSession;
 
 // Returns list of available capture devices that support video capture.
 + (NSArray<AVCaptureDevice *> *)captureDevices;
 // Returns list of formats that are supported by this class for this device.
 + (NSArray<AVCaptureDeviceFormat *> *)supportedFormatsForDevice:(AVCaptureDevice *)device;
 
 // Starts and stops the capture session asynchronously.
 - (void)startCaptureWithDevice:(AVCaptureDevice *)device
                         format:(AVCaptureDeviceFormat *)format
                            fps:(NSInteger)fps;
 // Stops the capture session asynchronously.
 - (void)stopCapture;
 
 @end
 
 NS_ASSUME_NONNULL_END