void onJobProcessingStart() {
    jobProcessingStartTimeMs = System.currentTimeMillis();
    cryptoJobMetrics.jobQueuingTimeInMs.update(jobProcessingStartTimeMs - jobSubmissionTimeMs);
  }
Notifies that the job processing has started for the corresponding CryptoJob
ambry-router/src/main/java/com/github/ambry/router/NonBlockingRouterMetrics.java