title: Xamarin forms MasterDetailPage Menu icon not shown on iOS
body: <p>I have Xamarin.Forms project. 
  I have MasterDetailPage inside NavigationPage. 
  I set icon property of the MasterDetailPage so that icon is supposed to be set as the top left position on the navigation bar. But it does not work. </p>
  
  <pre><code>public partial class App : Application
  {
      public App()
      {
          InitializeComponent();
  
          var masterDetailpage = new MasterDetailPage {
              Icon = "menuIcon.png",
              Master = new Page { Title = "Sample"},
              Detail = new Page()
          };
  
          MainPage = new NavigationPage(masterDetailpage);
      }
  }
  </code></pre>
  
  <p>This never works. If I put NavigationPage as MasterDetailPage's Detail property, and set icon on the Master. It works. 
  But it is very important to have MasterDetailPage inside NavigationPage and not vise versa.</p>