Service for exposing state and events of devices, such as media buttons.
Manipulates global policy for display backlight. Serves as the main “front
end” interface for usage by UX components; other protocols (such as
fuchsia.ui.scenic.Session and fuchsia.hardware.display.Controller) act as
implementation.
A listener for media buttons events. DeviceListenerRegistry.RegisterMediaButtonsListener
will consume this listener interface and call OnMediaButtonsEvent
when the
registered media buttons event occurs.