Pass settings model to ARDAppClient instead of individual settings.

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

-/*
- *  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 "ARDSettingsStore.h"
-
-static NSString *const kMediaConstraintsKey = @"rtc_video_resolution_media_constraints_key";
-static NSString *const kVideoCodecKey = @"rtc_video_codec_key";
-static NSString *const kBitrateKey = @"rtc_max_bitrate_key";
-
-NS_ASSUME_NONNULL_BEGIN
-@interface ARDSettingsStore () {
-  NSUserDefaults *_storage;
-}
-@property(nonatomic, strong) NSUserDefaults *storage;
-@end
-
-@implementation ARDSettingsStore
-
-- (NSUserDefaults *)storage {
-  if (!_storage) {
-    _storage = [NSUserDefaults standardUserDefaults];
-  }
-  return _storage;
-}
-
-- (nullable NSString *)videoResolutionConstraints {
-  return [self.storage objectForKey:kMediaConstraintsKey];
-}
-
-- (void)setVideoResolutionConstraints:(NSString *)constraintsString {
-  [self.storage setObject:constraintsString forKey:kMediaConstraintsKey];
-  [self.storage synchronize];
-}
-
-- (NSString *)videoCodec {
-  return [self.storage objectForKey:kVideoCodecKey];
-}
-
-- (void)setVideoCodec:(NSString *)videoCodec {
-  [self.storage setObject:videoCodec forKey:kVideoCodecKey];
-  [self.storage synchronize];
-}
-
-- (nullable NSNumber *)maxBitrate {
-  return [self.storage objectForKey:kBitrateKey];
-}
-
-- (void)setMaxBitrate:(nullable NSNumber *)value {
-  [self.storage setObject:value forKey:kBitrateKey];
-  [self.storage synchronize];
-}
-
-@end
-NS_ASSUME_NONNULL_END