title: Dark mode not enabling/disabling when using window.overrideUserInterfaceStyle on iPad
body: <p>I have successfully implemented the dark mode toggle by calling <code>window.overrideUserInterfaceStyle</code> in my app. When running the app in real iPhone or simulator, the function works fine.</p>
  
  <p>But when I run the same script in a iPad, only the <code>view.overrideUserInterfaceStyle</code> works. If I try to use <code>window.overrideUserInterfaceStyle</code> it does not update the trait collection (and neither call <code>traitCollectionDidChange(_)</code>.</p>
  
  <p>To change the style I am doing (style from white to dark):</p>
  
  <pre class="lang-swift prettyprint-override"><code>UIApplication.shared.connectedScenes.forEach { (scene: UIScene) in
      (scene.delegate as? SceneDelegate)?.window?.overrideUserInterfaceStyle = .dark //Just this one works on iPhone.
  }
  UIApplication.shared.delegate?.window??.overrideUserInterfaceStyle = .dark //Force
  UIWindow.appearance().overrideUserInterfaceStyle = .dark //Force
  </code></pre>
  
  <p>When the code is executed above, it should replace the color of all UIViews that are configured with <code>UIColor</code> for light and dark styles. Also call <code>traitCollectionDidChange(_)</code>. But none of these actions are happening on the iPad simulator.</p>
  
  <p>This code above only works on the iPhone real/simulator, it should work on the iPad simulator too. I don't have any iPad capable of dark style here.</p>
  
  <p>Maybe it's a bug on the simulator?</p>
  
  <p>I also tried to create a sample app and the style change works on iPad indeed, but since it's a clean project with no libraries it should work.</p>
  
  <p>I am also trying to minimize my app, still not working so I am afraid if it's a library creating a conflict.</p>
  
  <p>The problem also happens when using <code>UIApplication</code> setup instead of <code>UIScene</code>.</p>
  
  <p>I am using Xcode 11.3 and Swift 5 with some Cocoapod libraries.</p>