gluster: Adhere to vdsm verb glusterServicesAction

The VDSM verb to perform the gluster service action is modified to
glusterServicesAction. Changed the BLL code to adhere to the new
signature of the verb.

Change-Id: Ic89e819845e0945af4852f4516a46a488aa82d4b
Signed-off-by: Shubhendu Tripathi <shtripat@redhat.com>