Fix support orientation changes in Camera Preview

Bug: webrtc:8532
Change-Id: I2a3cc6974af711f1be6a55a6a1e04e7189175bd3
Reviewed-on: https://webrtc-review.googlesource.com/23220
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20702}

examples/objc/AppRTCMobile/ios/ARDVideoCallViewController.m

@@ -63,6 +63,10 @@
   [session addDelegate:self];
 }
 
+- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
+  return UIInterfaceOrientationMaskAll;
+}
+
 #pragma mark - ARDAppClientDelegate
 
 - (void)appClient:(ARDAppClient *)client

examples/objc/AppRTCMobile/ios/Info.plist

@@ -53,6 +53,9 @@
   <key>UISupportedInterfaceOrientations</key>
   <array>
     <string>UIInterfaceOrientationPortrait</string>
+    <string>UIInterfaceOrientationLandscapeLeft</string>
+    <string>UIInterfaceOrientationLandscapeRight</string>
+    <string>UIInterfaceOrientationPortraitUpsideDown</string>
   </array>
   <key>UIAppFonts</key>
   <array>