For streaming gRPC, do load balancing on requests instead of connections.

[vihangpatil]

Problem description

The load balancing on streaming gRPC happens on connections.
So, a single gRPC streaming connection is established with a single instance of prime.
Hence, that one instance of prime gets all the CCR gRPC requests.
#Instead, the load balancing should happen on requests instead of connections.

Reference

This article clearly explains the issue:
https://kubernetes.io/blog/2018/11/07/grpc-load-balancing-on-kubernetes-without-tears/

#715 has a dependency on this issue.