Allow for HPA configuration

[zprebosnyak-lm]

To allow the pods to utilize horizontal pod auto scaling the replicas and strategy.type fields of the deployment manifests need to be optionally turned on/off.

Propose modifying the deployment templates like so:

  {{- if .Values.notificationPublisher.replicas.enabled }}
  replicas: {{ .Values.notificationPublisher.replicas.replicaCount }}
  {{- end }}
  {{- if .Values.notificationPublisher.deployment.strategy.enabled }}
  strategy:
    type: {{ .Values.notificationPublisher.deployment.strategy.type }}
  {{- end }}

values.yaml

  replicas:
    enabled: true
    replicaCount: 1
  deployment:
    # -- The deployment strategy to use.
    strategy:
      enabled: true
      type: RollingUpdate