OTLP logs signal doesn't show up in OpenTelemetry Demo

[vordimous]

Describe the bug
I don't see any logs from zilla in opensearch, but logs are being produced when I enable the stdout exporter.

To Reproduce
Steps to reproduce the behavior:

1. Run the aklivity/opentelemetry-demo using the docker compose deployment.
2. wait for everything to start.
3. Fetch the orders from the Kafka topic: curl http://localhost:7114/orders. Produces an HTTP access log.
4. See all logs in OpenSearch Explorer
5. Searching for any of the configured attributes aren't available.
6. Scanning through the log bodys doesn't show anything relating to Zilla logs.

Expected behavior
Zilla logs are sent and parsed by the OpenTelemetry collector into OpenSearch.

[vordimous]

I have been able to find zilla is successfully sending event logs by filtering the OpenSearch logs with the below PPL query:

search source=otel
| where resource.service.name="zillaproxy"

when the zilla.yaml includes the service name attribute:

telemetry:
  attributes:
    service.name: "zillaproxy"