Comment 73 for bug 1953165

Reviewed: https://review.opendev.org/c/openstack/neutron/+/885272
Committed: https://opendev.org/openstack/neutron/commit/b37a2f80ee11715643929e1af809aa9edd814ed0
Submitter: "Zuul (22348)"
Branch: stable/yoga

commit b37a2f80ee11715643929e1af809aa9edd814ed0
Author: Brian Haley <email address hidden>
Date: Mon May 15 12:29:42 2023 -0400

    Start metadata proxy even if IPv6 DAD fails

    A recent change suppressed the IPv6 DAD failure and
    removed the address when multiple DHCP agents were
    configured on the same network,
    https://review.opendev.org/c/openstack/neutron/+/880957

    But it also changed the behavior to not enable IPv4
    metadata in this case. Restore the old behavior by
    not returning early in the DAD failure case. The callback
    that builds the config file was moved until after
    the address was bound to make the two steps more obvious.

    Conflicts:
        neutron/tests/unit/agent/metadata/test_driver.py

    Related-bug: #1953165
    Change-Id: I8436c6c9da9a2533ca27ff7312f5b2c7ea41e94f
    (cherry picked from commit 846003c4379124de6ffb3628ef1feb12a62a9cfa)
    (cherry picked from commit e7f85abae6a46a115582b80d1909e3565d859e9b)
    (cherry picked from commit 1a711f399abebff6572551ef4e3f7b92397caab5)