OpenOnuAdapter KvStore-removal of OnuAdapter flow entry not ensured at subsrciber flow removal

When removing subscriber flows the according OnuAdapter related flow (rule) entries must be removed from KvStore (ETCD). In current implementation this is not working in a safe way.

In commonly used ATT tests this effect gets visable only sporadically/randomly as the missing removal is sometimes (but not always) automatically corrected by the subsequent EAPOL flow assignment.

It should be clearly visible in DT scenario, but so far I have not found some existing Robot test with this processing that also provides according OnuAdapter logs.