Providing required priviledges to the mounted NFS volume

Providing required priviledges to the mounted NFS volume

Since, user ID on host and container differs, image-create
with NFS backend was failing with permission error. But even after
resolving permission error[1] the image was not getting created
on the nfs share as the NFS endpoint is not mounted successfully on
the container via puppet. This will be fixed by [2].

Now, adding two below changes in this patch,
[1]. chown glance:glance /var/lib/glance.
[2]. Proposing this solution to mount NFS endpoint on the host instead
     of mounting it on glance container, because mounting in container
     does not work as explained in LP Bug.

Closes-Bug: 1708629
Change-Id: Ib60cb0d179e7c117dc26440746154136aa9d163e
(cherry picked from commit
ed11f8ebcfbaf1fbbebb4c83e3201e462fee14ee)