packaging: setup: Hide irrelevant fields in configuration preview during setup

Few fields like NFS setup and Datacentre storage type are not relevant
when application mode is gluster. So they will not be displayed under
configuration preview during engine-setup if application mode is gluster.

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1020190
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>
Signed-off-by: ndarshan <dnarayan@redhat.com>
Change-Id: I9e4b3fffd37a62d9fc551dff178d5662d610ddd4