Support Panorama better when changing app bar visibility

[kamranayub]

If I want to hide/show different appbars, this works great on Pivot pages. However, on Panorama pages, the transitions will just stop as soon as you assign the PhoneApplicationPage.ApplicationBar property as well as when you set the Opacity to 0, BackgroundColor to transparent, etc.

The best workaround I have is to fake it by removing the buttons and setting the background color to Color.FromArgb(1, 0, 0, 0). The only issue is the background color change is jarring, but... a small price to pay, I guess.