The test case fails in pre-blockdev scenarios as it would pass RBD
parameters behind our back but succeeds after as we pass it in JSON form
which doesn't have that defect.
Cover both cases instead of the fake-caps version.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>