title: Adding UIView overlay to KeyWindow without covering alerts
body: <p>I'm trying to add a loading overlay to my application, and so far it works ok except that it covers alerts for some reason.</p>
  
  <ul>
  <li><p>The overlay is a fullscreen UIView that gets shown as such:</p>
  
  <pre><code>UIApplication.SharedApplication.KeyWindow.AddSubview(view);
  </code></pre></li>
  <li><p>The alerts I'm displaying afterwards are created as such:</p>
  
  <pre><code>var alertController = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
  
  alertController.ModalPresentationStyle = UIModalPresentationStyle.OverCurrentContext;
  
  viewController.PresentViewController(alertController, true, null);
  </code></pre></li>
  </ul>
  
  <p>The problem is that the alerts are displayed below the overlay despite having ModalPresentationStyle set to OverCurrentContext. Is there a way to force them to be displayed on top of everything?</p>