How to get pod uid as dimension for istio metrics

I followed this example to add dimensions to istio metrics. However, I don’t know how to add pod’s uid dimension. I tried [up|down]stream_peer_id but it’s something completely different.

I would need this to disambiguate the exact workload since two workloads of different types can share the name even in the same namespace. Right now I am doing it by checking services label selector. Beyond disambiguation, this would also improve lookup times.

Thanks in advance for any help, even if to tell me this is not possible at all.