Oracle dist based in RHEL dist and must be packaged using this [packaging files](https://github.com/kamailio/kamailio/tree/master/pkg/kamailio/obs)
This already documented at Oracle [README.md](https://github.com/kamailio/kamailio/blob/master/pkg/kamailio/oracle/README....)
I prefer to delete not maintained oracle packaging files and leave only `README.md` file.