title: Windows Phone navigation buttons overlap with screen resolution
body: <p><a href="https://i.stack.imgur.com/SrCW3.jpg"><img src="https://i.stack.imgur.com/SrCW3.jpg" alt="Nokia 820 vs Nokia 635"></a> below you'll see a screen running in Windows Phone 8.1 one 2 devices.  Both are claiming to have Viewport Width and Height of 800x480 however as you can see from the image the 635's nav buttons are overlapping the game area.</p>
  
  <p>I have checked various properties in GraphicsDevice.Adapter and GraphicsDevice.Viewport, but they are both the same!</p>
  
  <p>The screen is running within C# UWP Monogame code.  I set the PrefferedBackBufferWidth and Height to 480x800.</p>
  
  <p>How can you tell if the nav buttons with take up part of the screen?</p>