It is available in Neutron lib since version 1.16 so pretty long time
now.
Also use segment api definition from neutron-lib, it's available
since version 1.19.0. The api definition from neutron-lib also
avoids circulary dependency b/w standard-attr-segment and segment
extension[1].
[1] https://review.opendev.org/c/openstack/neutron-lib/+/577866
Change-Id: I13699f8c494a15d8bb9e13f767f2725f7cab9f4f
Related-Bug: #1765008
Standard attributes has been added to segment [1] and we need
a shim extension to indicate this.
[1] https://review.openstack.org/#/c/558318/
Change-Id: I761fa7cb684a457726dedc95fde92d6adb86f5e4
Partial-Bug: #1765008