Follow state changes for brightness & gesture preference

[CarlosOlivo]

Complement of #442

I think I found an error in your library @Maxr1998, or I am using it incorrectly?

D/SettingsFragment: appPreferences.exoPlayerAllowSwipeGestures = true
D/SettingsFragment: swipeGesturesPreference.checked = false
D/SettingsFragment: swipeGesturesPreference.getBoolean(false) = false

Could you check why it returns different values?

[Maxr1998]

D/SettingsFragment: appPreferences.exoPlayerAllowSwipeGestures = true
D/SettingsFragment: swipeGesturesPreference.checked = false
D/SettingsFragment: swipeGesturesPreference.getBoolean(false) = false

Could you check why it returns different values?

That's normal, when building the preference tree, it isn't attached to the context yet, so it returns default values. Once the screen builder finishes, it resolves all data from SharedPreferences. Using appPreferences is the correct choice in your case.
Could you reformat the file to move the && into the same line, and insert newlines to the callback?