after reading this article I'm trying to cleanup metrics going out of Spark 3.0.1. Here is my servicemonitor.yml file:

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  labels:
    app: spark3
    release:  prometheus
  name: spark3-servicemonitor
spec:
  endpoints:
  - interval: 5s
    port: spark-ui
    path: /metrics/prometheus
    relabelings:
    # Rename metrics
      - sourceLabels: [__name__]
        targetLabel: __name__
        regex: 'metrics_spark_driver_.+_StreamingMetrics_([a-zA-Z_]{1,})_Value'
        replacement: 'spark_driver_$1'
  namespaceSelector:
    matchNames:
    - default
  selector:
    matchLabels:
      spark-version: "3"

I expect the following transformation: metrics_spark_driver_whateverappid_StreamingMetrics_streaming_lastCompletedBatch_totalDelay_Value -> spark_driver_streaming_lastCompletedBatch_totalDelay however the relabelling does not seem to work. Could you please assist me on this subject?