Able to configure logging format (JSON) in kubelet arg through EKS-A cluster spec

**What would you like to be added**:

We would like to change the logging format (e.g. JSON) in kubelet arg through EKS-A cluster spec.

https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/

> `--logging-format`: Sets the log format. Permitted formats: text, json (gated by LoggingBetaOptions). (DEPRECATED: This parameter should be set via the config file specified by the Kubelet's --config flag. See kubelet-config-file for more information.)

As the arg `--logging-format` being deprecated, instead we will need to pass the config in `KubeletConfiguration` object.

**Why is this needed**:

Some logging management system like Greylog only expects JSON format.

Start by tracing how the EKS-A cluster spec is converted into kubelet arguments or configuration, then compare that path with Kubernetes' KubeletConfiguration documentation linked in the issue. Done means a cluster spec can request JSON kubelet logging and the setting reaches the kubelet without relying on the deprecated --logging-format argument.

Written by the indexing model from the issue text.