[NGINX Ingress Controller OpenTelemetry]: The integration does not work with the default mapping

### Integration Name

Nginx Ingress Controller OpenTelemetry Logs [nginx_ingress_controller_otel]

### Dataset Name

_No response_

### Integration Version

0.2.2

### Agent Version

EDOT 9.2

### Agent Output Type

elasticsearch

### Elasticsearch Version

8.19

### OS Version and Architecture

N/A

### Software/API Version

N/A

### Error Message

No errors are displayed

### Event Original

_No response_

### What did you do?

- Install the NGINX Ingress Controller (OpenTelemetry) Integration in an Elastic Cluster.

- Configure log collection in the Kubernetes cluster (e.g., via the Helm Chart) according to the integration's documentation to parse the logs (matching the transformation/Helm Chart modification made).

- Open the Dashboard of the integration

### What did you see?

NGINX Ingress Controller (OpenTelemetry) Integration stores parsed log fields in the `body.structured` field. In its current form, this field is a Flattened Field which is not compatible with ESQL (Elasticsearch Query Language).

### What did you expect to see?

Fully working dashboard panels.

### Anything else?

The configuration is very difficult to deploy.