title: Resize FormSheet does not get affected
body: <p>I am displayin my viewcontroller in the formsheet, but the default size is more than I need, therefore, I am trying to resize to match my requirement, but nothing has changing.</p>
  
  <pre><code>var vc = new WSViewController();
  vc.ModalPresentationStyle = UIModalPresentationStyle.FormSheet;
  vc.ModalTransitionStyle = UIModalTransitionStyle.CrossDissolve;
  PresentViewController(vc, true, () =&gt; {
      vc.View.Superview.Frame = new CGRect(0, 0, 200, 200);
      vc.View.Superview.Center = View.Center;
  });
  </code></pre>