Currently the cinder nfs backend leaves out few options in a
multi backend deployment. It works in single nfs backend deployment
as devstack-plugin-nfs correctly configures all options[1].
We can clearly see the difference between what devstack-plugin-nfs
configures[1] and what devstack nfs configures[2].
Following options are missing which are added by this patch.
* nas_host
* nas_share_path
* nas_secure_file_operations
* nas_secure_file_permissions
* nfs_snapshot_support
[1] dd12367f90/devstack/plugin.sh (L60-L68)
[2] a52041cd3f/lib/cinder_backends/nfs (L32-L34)
Change-Id: I03cad66abb3c6f2ae1d5cf943ac952a30961f783
aa47cb34ae