Any symbols (including class properties) that should be visible
outside the module it's defined in need to be defined as global.
For now gjs still allows the access for 'const', but get rid of
the warnings spill now by changing it.
https://bugzilla.gnome.org/show_bug.cgi?id=785084
It is not always possible to determine the type of audio device that
got plugged in. Add a system modal dialog to query the user in that
case and export in on the bus to gnome-settings-daemon.
https://bugzilla.gnome.org/show_bug.cgi?id=760284