Disable Cassandra exporter by default. (#21659)

A saner default is to disable the exporter and service monitor by default as not everyone is using Prometheus let alone Prometheus Operator. Also changing the key name from servicemonitor to serviceMonitor as it seems to be the standard way of spelling it across charts.

Signed-off-by: Naseem <naseem@transit.app>

incubator/cassandra/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v1
 name: cassandra
-version: 0.14.4
-appVersion: 3.11.5
+version: 0.15.0
+appVersion: 3.11.6
 description: Apache Cassandra is a free and open-source distributed database management
   system designed to handle large amounts of data across many commodity servers, providing
   high availability with no single point of failure.

incubator/cassandra/templates/servicemonitor.yaml

@@ -1,4 +1,4 @@
-{{- if and .Values.exporter.enabled .Values.exporter.servicemonitor.enabled }}
+{{- if and .Values.exporter.enabled .Values.exporter.serviceMonitor.enabled }}
 apiVersion: monitoring.coreos.com/v1
 kind: ServiceMonitor
 metadata:
@@ -9,8 +9,8 @@ metadata:
     chart: {{ template "cassandra.chart" . }}
     release: {{ .Release.Name }}
     heritage: {{ .Release.Service }}
-    {{- if .Values.exporter.servicemonitor.additionalLabels }}
-{{ toYaml .Values.exporter.servicemonitor.additionalLabels | indent 4 }}
+    {{- if .Values.exporter.serviceMonitor.additionalLabels }}
+{{ toYaml .Values.exporter.serviceMonitor.additionalLabels | indent 4 }}
     {{- end }}
 spec:
   jobLabel: {{ template "cassandra.name" . }}

incubator/cassandra/values.yaml

@@ -2,7 +2,7 @@
 ## ref: https://hub.docker.com/r/library/cassandra/
 image:
   repo: cassandra
-  tag: 3.11.5
+  tag: 3.11.6
   pullPolicy: IfNotPresent
   ## Specify ImagePullSecrets for Pods
   ## ref: https://kubernetes.io/docs/concepts/containers/images/#specifying-imagepullsecrets-on-a-pod
@@ -212,10 +212,9 @@ backup:
 ## Cassandra exported configuration
 ## ref: https://github.com/criteo/cassandra_exporter
 exporter:
-  # If exporter is enabled this will create a ServiceMonitor by default as well
-  enabled: true
-  servicemonitor:
-    enabled: true
+  enabled: false
+  serviceMonitor:
+    enabled: false
     additionalLabels: {}
       # prometheus: default
   image: