gluster: Make set option a step of create volume

Modified the CreateGlusterVolumeCommand to invoke
SetGlusterVolumeOptionCommand as a child step of itself.

Also enhanced the job message for CreateGlusterVolume
to display name of the volume being created.

Change-Id: Ie0f22e9862584f1a616fcc01e8a80b7d5a5ffc78
Signed-off-by: Shireesh Anjal <sanjal@redhat.com>