No APM agent token visible in Kibana with local Tilt setup

When using `tilt` setup, we can use APM agents with the `http://localhost:8200` endpoint.

However, the secret token (or API key) that APM agents have to use is not shown in the Kibana UI:

The secret token is still generated and used by apm-server and we can use the following `kubectl` command to retrieve it:

```
kubectl get secret/apm-server-apm-token -o go-template='{{index .data "secret-token" | base64decode}}'
```
This is identical to [this command in our documentation](https://www.elastic.co/guide/en/cloud-on-k8s/current/k8s-apm-connecting.html#k8s-apm-secret-token) but with a different server name.

Reproduce the local Tilt setup and open the Kibana UI for the APM server. Compare what the UI exposes with the secret retrieved by the documented kubectl command, then trace the relevant Kibana UI entry point. Done means the generated secret token or API key is visible for agents to use.

Written by the indexing model from the issue text.