[kube-state-metrics] Support elastic agent sidecar

[dominic-paul-92]

Is your feature request related to a problem ?

Currently the standalone elastic agent needs to be separately deployed to collect kube state metrics.
If auto sharding enabled for KSM, it is an overhead to deploy a scaled elastic agent to connect to multiple sharded KSM instance. A one to one mapping is required between the pods.

Describe the solution you'd like.

If the standalone elastic agent can be deployed as a sidecar container, it will be easier to manage the deployment.

Something similar is suggested by elastic. But this introduce the overhead of using k8s Kustomization on top of helm chart.

Instead, it will be good to have an optional container in the helm chart of KSM, where a user can deploy elastic agent as a sidecar container.

Describe alternatives you've considered.

NONE

Additional context.

No response

[dotdc]

Should be fixed by #3861