[KYUUBI #6006][HELM] Support additional labels for service monitor

# 🔍 Description
## Issue References 🔗

This pull request fixes #6006

## Describe Your Solution 🔧

Add new value `additionalLabels` in `serviceMonitor` to support templating the labels so that Prometheus can discover it

## Types of changes 🔖

- [ ] Bugfix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

## Test Plan 🧪

#### Behavior Without This Pull Request ⚰️
Our Prometheus is based on `kube-prometheus-stack` chart, so it requires label `release: kube-prometheus-stack`
The current setup of kyuubi helm does not allow the ServiceMonitor can be discovered by Prome because it's not able to pass extra labels to it.

#### Behavior With This Pull Request 🎉
The MR enables templating extra labels

#### Related Unit Tests

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# Checklist 📝

- [x] This patch was not authored or co-authored using [Generative Tooling](https://www.apache.org/legal/generative-tooling.html)

**Be nice. Be informative.**

Closes #6019 from sudohainguyen/helmchart.

Closes #6006

69a86c5 [Hai Nguyen] chore: simplify labels values
ed3fb0e [Hai Nguyen] [KYUUBI #6006] Support additional labels for service monitor

Authored-by: Hai Nguyen <[email protected]>
Signed-off-by: Cheng Pan <[email protected]>

charts/kyuubi/templates/kyuubi-servicemonitor.yaml

@@ -22,6 +22,9 @@ metadata:
   name: {{ .Release.Name }}
   labels:
     {{- include "kyuubi.labels" . | nindent 4 }}
+    {{- if .Values.serviceMonitor.labels }}
+    {{- toYaml .Values.serviceMonitor.labels | nindent 4 }}
+    {{- end }}
 spec:
   selector:
     matchLabels:

charts/kyuubi/values.yaml

@@ -297,6 +297,8 @@ serviceMonitor:
   # The endpoints section in a ServiceMonitor specifies the metrics information for each target endpoint.
   # This allows you to collect metrics from multiple Services across your Kubernetes cluster in a standardized and automated way.
   endpoints: []
+  # Additional labels that can be used so ServiceMonitor will be discovered by Prometheus
+  labels: {}
 
 # Rules for the Prometheus Operator
 prometheusRule: