m-portal-permissionstore: try to reconnect on idle if DBus connection is closed

This change also keeps the plugin always activated, regardless of whether the
DBus connection is closed or not, which is useful when the dbus service is
restarted.
6 jobs for dbus-restart-fix in 2 minutes and 9 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Container
passed container_fedora #13974377

00:00:17

passed container_ubuntu #13974378

00:00:27

 
  Build
passed build_on_fedora_no_docs #13974380

00:01:23

passed build_on_fedora_with_docs #13974379

00:00:42

passed build_on_ubuntu_no_gir #13974382

00:00:52

passed build_on_ubuntu_with_gir #13974381

00:01:23