SSH over IPv4 when using a storage network

A storage network can be configured to connect
VMs in scenario tests to their shares. When
using a storage network, we don't need to force
the private network that we use to SSH to the
VM to be on a particular IP version.

We need the private network subnet to be of
a particular IP version only when there is
no storage network, and we're connecting to
shares over the same network as SSH.

Change-Id: If1d581730c42b060e74600ef2a05298921b1a3c6
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>
diff --git a/manila_tempest_tests/config.py b/manila_tempest_tests/config.py
index de5cf58..7993693 100644
--- a/manila_tempest_tests/config.py
+++ b/manila_tempest_tests/config.py
@@ -290,5 +290,11 @@
                help="Default size in GB for shares created by share tests."),
     cfg.BoolOpt("run_ipv6_tests",
                 default=False,
-                help="Enable or disable running IPv6 tests."),
+                help="Enable or disable running IPv6 NFS scenario tests. "
+                     "These tests validate that IPv6 export locations work, "
+                     "and that access can be provided to IPv6 clients. When "
+                     "you do not specify a storage_network, the tests will "
+                     "attempt to create an IPv6 subnet on the project network "
+                     "they create for ping and SSH to the client test VM "
+                     "where data path testing is performed."),
 ]