Devstack's lib/cinder set the my_ip on cinder side but it
hard-code it with HOST_IP[1]. It is no issue for IPv4 env
but when you build or run the IPv6 job then this ip is left
to set with IPv6. my_ip should be set to HOST_IP or HOST_IPV6
based on SERVICE_IP_VERSION value.
As part of Train community goal 'Support IPv6-Only Deployments',
we will expand the 'devstack-tempest-ipv6' job to do IPv6-only
deployments verification so we need fix the the my_ip setting.
Closes-Bug: #1838250
Depends-On: https://review.opendev.org/#/c/677524/
[1]6aeaceb0c4/lib/cinder (L231)
Change-Id: I71c74e46467a5d3c1bf9c7d683f364cba7cf9d80
d331fa7a2d