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
gnome-settings-daemon monitors smartcard insertion and removal
events on the system and then exports a model of the current
smartcard topology over the bus using the D-Bus ObjectManager interface.
This commit adds the support code needed in gnome-shell to talk to
the gnome-settings-daemon service.
A future commit will use this code to inform the login screen
when a user inserts a smartcard (so it can react appropriately)
https://bugzilla.gnome.org/show_bug.cgi?id=683437