StatusBar style fixing

Hello there,

There is statusBar options in navigationBar component. But barStyle for statusBar is wrong written.

https://github.com/shoutem/ui/blob/5cc29e862a5c1da540b8f2a660b8f91e06abc74b/components/NavigationBar/NavigationBar.js#L45

im guessing; "default" should be replaced with 'dark-content'

Thanks!