[occm] Allow exposing monitoring port for separate service monitor

[HaoruiPeng]

/kind feature

What happened:

Currently the occm daemonSet only exposes the port 10258 and binds 0.0.0.0 for service monitor when .Values.serviceMonitor.enabled set to true.

If we want to create a service monitor separately in another monitoring chart instead of using the occm Helm chart, we need to patch it and run helm upgrade to expose the port.

What you expected to happen:

We want to have an additional value config to allow exposing the port without enabling serviceMonitor, something like this simply:

 {{- if or .Values.serviceMonitor.enabled .Values.allowMonitoring }}
  - --bind-address=0.0.0.0
  {{- else }}
  - --bind-address=127.0.0.1
  {{- end }}


  {{- if or .Values.serviceMonitor.enabled .Values.allowMonitoring }}
  ports:
  - containerPort: 10258
    hostPort: 10258
    name: http
    protocol: TCP
  {{- end }}

How to reproduce it:

Anything else we need to know?:
I can create the PR is the feature request is approved.

Environment:

• openstack-cloud-controller-manager(or other related binary) version:
• OpenStack version:
• Others: