Hi,
If I am correct this is not possible currently, but I remember I was working on a solution, but unfortunately I stopped at some point because kolla upstream didn't want to maintain.
In attachment you can find patches for kolla and kolla-ansible and our idea.
We added python script to kolla container and provide netplan style configuration by kolla-ansible ..so openvswitch starts and configured networking as it was set in configuration (if i remember ...it is quite long time....and of course it was not final version ...but if i remember it somehow worked).
So, you can check it and maybe we can discuss this feature again :)
Thanks,
Kevko