Revert of Add bitrate section to settings view controller. (patchset #1 id:1 of https://codereview.webrtc.org/2473783003/ )

Reason for revert:
The usage of UIKeyboardTypeASCIICapableNumberPad enum (available only for iOS 10.0), is breaking the build of AppRTCMobile on devices with lesser os.
To re-land the UIKeyboardTypeASCIICapableNumberPad should be replaced with UIKeyboardTypeNumberPad

Original issue's description:
> Add bitrate section to settings view controller.
>
> BUG=webrtc:6654
>
> Committed: https://crrev.com/3babb99039478c36be58171c5409eac07ae153e5
> Cr-Commit-Position: refs/heads/master@{#14952}

TBR=magjed@webrtc.org,kthelgasson@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6654

Review-Url: https://codereview.webrtc.org/2488653002
Cr-Commit-Position: refs/heads/master@{#14972}

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

@@ -172,7 +172,7 @@ static NSString *const barButtonImageString = @"ic_settings_black_24dp.png";
 #pragma mark - Private
 - (void)showSettings:(id)sender {
   ARDSettingsViewController *settingsController =
-      [[ARDSettingsViewController alloc] initWithStyle:UITableViewStyleGrouped
+      [[ARDSettingsViewController alloc] initWithStyle:UITableViewStylePlain
                                  mediaConstraintsModel:[[ARDMediaConstraintsModel alloc] init]];
   UINavigationController *navigationController =
       [[UINavigationController alloc] initWithRootViewController:settingsController];

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

@@ -12,12 +12,6 @@
 #import "ARDMediaConstraintsModel.h"
 
 NS_ASSUME_NONNULL_BEGIN
-
-typedef NS_ENUM(int, ARDSettingsSections) {
-  ARDSettingsSectionMediaConstraints = 0,
-  ARDSettingsSectionBitRate
-};
-
 @interface ARDSettingsViewController () {
   ARDMediaConstraintsModel *_mediaConstraintsModel;
 }
@@ -85,47 +79,28 @@ typedef NS_ENUM(int, ARDSettingsSections) {
 #pragma mark - Table view data source
 
 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
-  return 2;
-}
-
-- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
-  if ([self sectionIsMediaConstraints:section]) {
-    return self.mediaConstraintsArray.count;
-  }
-
   return 1;
 }
 
-#pragma mark - Index path helpers
-
-- (BOOL)sectionIsMediaConstraints:(int)section {
-  return section == ARDSettingsSectionMediaConstraints;
+- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
+  return self.mediaConstraintsArray.count;
 }
 
-- (BOOL)sectionIsBitrate:(int)section {
-  return section == ARDSettingsSectionBitRate;
+#pragma mark - Table view delegate
+
+- (BOOL)sectionIsMediaConstraints:(int)section {
+  return section == 0;
 }
 
 - (BOOL)indexPathIsMediaConstraints:(NSIndexPath *)indexPath {
   return [self sectionIsMediaConstraints:indexPath.section];
 }
 
-- (BOOL)indexPathIsBitrate:(NSIndexPath *)indexPath {
-  return [self sectionIsBitrate:indexPath.section];
-}
-
-#pragma mark - Table view delegate
-
 - (nullable NSString *)tableView:(UITableView *)tableView
          titleForHeaderInSection:(NSInteger)section {
   if ([self sectionIsMediaConstraints:section]) {
     return @"Media constraints";
   }
-
-  if ([self sectionIsBitrate:section]) {
-    return @"Maximum bitrate";
-  }
-
   return @"";
 }
 
@@ -134,11 +109,6 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   if ([self indexPathIsMediaConstraints:indexPath]) {
     return [self mediaConstraintsTableViewCellForTableView:tableView atIndexPath:indexPath];
   }
-
-  if ([self indexPathIsBitrate:indexPath]) {
-    return [self bitrateTableViewCellForTableView:tableView atIndexPath:indexPath];
-  }
-
   return [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                 reuseIdentifier:@"identifier"];
 }
@@ -188,44 +158,5 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   return indexPath;
 }
 
-#pragma mark - Table view delegate(Bitrate)
-
-- (UITableViewCell *)bitrateTableViewCellForTableView:(UITableView *)tableView
-                                          atIndexPath:(NSIndexPath *)indexPath {
-  NSString *dequeueIdentifier = @"ARDSettingsBitrateCellIdentifier";
-  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:dequeueIdentifier];
-  if (!cell) {
-    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
-                                  reuseIdentifier:dequeueIdentifier];
-
-    UITextField *textField = [[UITextField alloc]
-        initWithFrame:CGRectMake(10, 0, cell.bounds.size.width - 20, cell.bounds.size.height)];
-    textField.placeholder = @"Enter max bit rate (kbps)";
-    textField.keyboardType = UIKeyboardTypeASCIICapableNumberPad;
-
-    // Numerical keyboards have no return button, we need to add one manually.
-    UIToolbar *numberToolbar =
-        [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 50)];
-    numberToolbar.items = @[
-      [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace
-                                                    target:nil
-                                                    action:nil],
-      [[UIBarButtonItem alloc] initWithTitle:@"Apply"
-                                       style:UIBarButtonItemStyleDone
-                                      target:self
-                                      action:@selector(numberTextFieldDidEndEditing:)]
-    ];
-    [numberToolbar sizeToFit];
-
-    textField.inputAccessoryView = numberToolbar;
-    [cell addSubview:textField];
-  }
-  return cell;
-}
-
-- (void)numberTextFieldDidEndEditing:(id)sender {
-  [self.view endEditing:YES];
-}
-
 @end
 NS_ASSUME_NONNULL_END