gluster: starting glusterd after install

glusterd service was not started after installing. Added an event
which will get triggered after the gluster installation which starts
the glusterd service.

Change-Id: I4f65ea6cbb54c844fb42ad1a14c61c438ac0865a
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>