isAppearanceLightNavigationBars
Checks if the foreground of the navigation bar is set to light.
This method always returns false on API <26.
If this value is being set in the theme (via windowLightNavigationBar), then the correct value will only be returned once attached to the window.
Once this method is called, modifying `systemUiVisibility` directly to change the appearance is undefined behavior.
Return
true if the foreground is light