Reland of name AppRTCDemo on Android and iOS to AppRTCMobile

webrtc/examples/objc/AppRTCMobile/ios/main.m

 /*
  *  Copyright 2013 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 <UIKit/UIKit.h>
 
 #import "ARDAppDelegate.h"
 
 int main(int argc, char* argv[]) {
   @autoreleasepool {
     return UIApplicationMain(
         argc, argv, nil, NSStringFromClass([ARDAppDelegate class]));
   }
 }