Android: Full Screen Support for Modal Navigation Page

Hello All,
I am new to the Xamarin and currently having a little problem with a navigation page.

1. The application is using Master-Page based navigation.
2. On one of the pages, I wish to display a modal page, which will be used for image viewing

3. The modal page must be full screen and I did the following to hide the System UI

   var decorView = Window.DecorView;
   StatusBarVisibility uiOptions = decorView.SystemUiVisibility;
   var newUiOptions = (int)uiOptions;

   newUiOptions |= (int)SystemUiFlags.LowProfile;
   newUiOptions |= (int)SystemUiFlags.Fullscreen;
   newUiOptions |= (int)SystemUiFlags.HideNavigation;
   newUiOptions |= (int)SystemUiFlags.Immersive;
   newUiOptions |= (int)SystemUiFlags.ImmersiveSticky;
   newUiOptions |= (int)SystemUiFlags.LayoutFullscreen;

   decorView.SystemUiVisibility = (StatusBarVisibility)newUiOptions;

4. The result is that the status bar is cleared but not hidden. I also tried the following without success

   DecorView.SystemUiVisibility = StatusBarVisibility.Hidden;

Attached is the image of the screen, taken on Galaxy S6 Edge, running Android 5.0.2

The screenshot is here https://drive.google.com/open?id=0B9Z9U0ARfxuyRFdLbkFBSGw0dTQ

Any help, please?