Support customSecretName for nri-statsd

[RoseSecurity]

Description

Right now, the nri-statsd chart requires the API key to be hardcoded in the values.yaml or injected during the helm install, but it would be better if a customSecretName could be utilized to reference the secret location like the other nri-bundle elements utilize.

Acceptance Criteria

Before:

global:
   insightsKey: ""

After:

global:
  customSecretName: nri-statsd-key

Implementation

• Maybe something like this for the _helpers.tpl:

{{/*
Return the customSecretName where the New Relic Insights API key is being stored
*/}}
{{- define "nri-statsd.customSecretName" -}}
{{- if .Values.global }}
  {{- if .Values.global.customSecretName }}
      {{- .Values.global.customSecretName -}}
  {{- else -}}
      {{- .Values.customSecretName | default "" -}}
  {{- end -}}
{{- else -}}
    {{- .Values.customSecretName | default "" -}}
{{- end -}}
{{- end -}}

At the bottom:

{{/*
Returns if the template should render, it checks if the required values
insightsKey or customSecretName and cluster are set.
*/}}
{{- define "nri-statsd.areValuesValid" -}}
{{- $cluster := include "nri-statsd.cluster" . -}}
{{- $insightsKey := include "nri-statsd.insightsKey" . -}}
{{- $customSecretName := include "nri-statsd.customSecretName" . -}}
{{- and $cluster (or $insightsKey $customSecretName) }}
{{- end -}}

Then update the configmap to use either value

[workato-integration]

https://new-relic.atlassian.net/browse/NR-256275