Bug 6543: Changed the default value of port-name

Bug 6543: Changed the default value of port-name

This patch changed the default value of the parameter "port-name" for
the odl-vtn-manager-neutron feature to "eth1" in order to make the CSIT
for the feature work well. As of now, the parameter is not configurable,
and the default value is always used. However, in the ODL CSIT
environment, this parameter needs to be "eth1".

This change is a tentative fix. Ideally, the parameter "port-name"
should be configurable. That improvemnt is tracked as Bug 6599.

Change-Id: Id059618d975dc4982d498c7ab931c55026ba61bb
Signed-off-by: gvrangan <venkatrangang@hcl.com>