Use glib.timeout_add instead of gtk.timeout_add

gtk.timeout_add is deprecated, as this message says:
    GtkDeprecationWarning: gtk.timeout_add is deprecated,
        use gobject.timeout_add instead

Change-Id: Ie108f46eebe7c7ed247e5c2428957fc7201909ad
Merge "Use glib.timeout_add instead of gtk.timeout_add"