Add driver ui port executor pod label for prometheus metrics

[edingroot]

Add spark.yelp.com/driver_ui_port pod label.

Test reinstalling service_configuration_lib in jupyter and start a spark session, check executor pod's pod labels:

$ kps get pod -o json $pod | jq '.metadata' | grep ui_port

    "spark.yelp.com/driver_ui_port": "39091",

[88manpreet]

Offline discussion with chi: This is to expose port of spark ui inside grafana dashboard for easy access at a single place.