Remove the old code to set the status bar behavior values

[bijington]

This might not be completely necessary as it doesn't currently conflicting with our samples page but... the code removed here does conflict if a developer opts for just providing a value into the StatusBarBehavior (e.g.

<Page.Behaviors>
        <mct:StatusBarBehavior
              StatusBarColor="Red"
              StatusBarStyle="{Binding Source={x:Reference Page}, Path=BindingContext.StatusBarStyle}" />
 </Page.Behaviors>

The resulting behaviour will be that no Color will exist and the status bar (at least on iOS) will be Black.