Do not assume the kubernetes cluster domain

[adrianlzt]

Summary

Adding the suffix "cluster.local" in the service domain breaks compatibility with k8s clusters with custom domains.

Just defining until ".svc" will use the "search" in /etc/resolv.conf to complete the domain with the correct value.

Checklist

• [ ] reference any related issues
• [ ] updated docs
• [ ] updated unit tests
• [ ] updated UPGRADING.md
• [ ] add appropriate tag (improvement / bug / etc)
• [x] ready for review