Remove the z flag from glance-api's service directory. The service
directory does not need to be shared with other containers, and
podman fails to apply setting with glance is using NFS (i.e.
/var/lib/glance/images is a mount point).
Also update the NFS mount options to use svirt_sandbox_file_t, which
is consistent with the parent service directory.
Closes-Bug: #1834857
Closes-Bug: #1844465
Change-Id: I7e135615fb53815ce14a3bcfec42b28f86d6dbae
aa1f4bf621