Fix network-environment file location during OSP10 upgrade
Fix network-environment file location during OSP10 upgrade

Currently both network-environment-v6.yaml and network-environment.yaml
files get created by Infrared so the network_environment_file always gets
set to the IPv4 variant which doesn't work for IPv6 environments. This
change looks for the network environment file inside the overcloud deploy
script and sets the network_environment_file file according to that result.

Change-Id: I08da9f7676af8451b82329341271df8128ea90ee

okolisny/InfraRed,redhat-openstack/infrared,okolisny/InfraRed,okolisny/InfraRed,redhat-openstack/infrared,redhat-openstack/infrared