grilo: Add vala bindings for Key COMPOSER
grilo: Add vala bindings for Key COMPOSER

Currently Grilo returns an error when the Key COMPOSER
is used, this commit adds the binding to allow the key
to function properly.

https://gitlab.gnome.org/GNOME/grilo/issues/2

jasuarez/grilo,grilofw/grilo,grilofw/grilo,GNOME/grilo,grilofw/grilo,GNOME/grilo,jasuarez/grilo,jasuarez/grilo