[Kubernetes] Use hostname + pod UID for shuffle manager caching

When a pod restarts, it uses the same hostname and shuffle port. Now when fetcher threads connects to download the shuffle data it will use the cached connection info and since the pod has died it's shuffle data will also get cleaned up. When the pod restarts, it receives connection from clients to download specific shuffle data but the daemon will not have it because of the restart.

In ShuffleManager.java's knownSrcHosts the key should be updated to HostInfo which is a combination of host+port and the host's unique ID. The host host Id changes when a node is killed or restarted.