[SPARK-52623] Add spark.ui.port to Spark History Server example

[dongjoon-hyun]

What changes were proposed in this pull request?

This PR aims to add spark.ui.port to Spark History Server example.

Why are the changes needed?

To add 18080 to the K8s Service entity.

Does this PR introduce any user-facing change?

No, this is an example.

How was this patch tested?

Manual test.

$ kubectl get sparkapp
NAME                   CURRENT STATE    AGE
spark-history-server   RunningHealthy   8m53s

$ kubectl get svc spark-history-server-0-driver-svc
NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                       AGE
spark-history-server-0-driver-svc   ClusterIP   None         <none>        7078/TCP,7079/TCP,18080/TCP   8m55s

Was this patch authored or co-authored using generative AI tooling?

No.

[dongjoon-hyun]

cc @Ferdinanddb

[dongjoon-hyun]

Merged to main.