Expose all fields below spec in eck-resources Helm charts

[thbkrkr]

Follow-up of #6249, there are 4 fields that are not exposed in the eck-elasticsearch Helm chart:

spec:
  image:
  podDisruptionBudget:
  serviceAccountName:
  revisionHistoryLimit:

Let's make a pass on other elastic resources to verify that their Helm chart is ISO with the CRD....

[alanspencer24]

We also need this issue to be worked because we are working in an air-gapped environment. Per your documentation below

https://www.elastic.co/guide/en/cloud-on-k8s/current/k8s-air-gapped.html

we can't specify the image in your CRD until the image value is exposed in these charts

[thbkrkr]

Only Helm eck-elasticsearch chart has unexposed fields. In the other eck-resources Helm charts, the whole spec is exposed.

[thbkrkr]

Closed by #6492.