gluster: Fix for json-rpc issue wrt gluster commands.

This patch adds spec file entry for missing apiwrapper
module and moved vdsmapi-gluster-schema.json from
vdsm/gluster/ to vdsm/rpc/.

Change-Id: Ia8cf744813f7bbfbf6e2bf073b28b88e0d3f304f
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1124481
Signed-off-by: ndarshan <dnarayan@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/33007
Reviewed-by: Dan Kenigsberg <danken@redhat.com>