[8.19] (backport #8696) Fix otel extension status reporting

[mergify]

What does this PR do?

Fix a bug where Elastic Agent would enter a failed state if components were running as beats receivers and the otel collector also had an extension defined via hybrid mode.

The result would be the following agent status:

┌─ fleet
│  └─ status: (STOPPED) Not enrolled into Fleet
└─ elastic-agent
   ├─ status: (FAILED) OTel manager failed: pipeline status id extensions is not a pipeline
   ├─ extensions
   │  ├─ status: StatusOK
   │  └─ extension:health_check/v2
   │     └─ status: StatusOK

Why is it important?

We should report status for otel extensions correctly.

Checklist

• I have read and understood the pull request guidelines of this project.
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• [ ] I have added an entry in ./changelog/fragments using the changelog tool
• [ ] I have added an integration test or an E2E test

How to test this PR locally

Build agent locally and run it with the following configuration:

outputs:
  default:
    type: elasticsearch
    hosts: [127.0.0.1:9200]
    username: "elastic"
    password: ""

agent:
  monitoring:
    enabled: true
    _runtime_experimental: otel

inputs: []

# Embedded Otel configuration
receivers:
  nop:
exporters:
  nop:
extensions:
  health_check/v2:
service:
  extensions: [health_check/v2]
  pipelines:
    logs:
      receivers: [nop]
      exporters: [nop]

Then run elastic-agent status. You should see the extension status and the statuses of monitoring components:

┌─ fleet
│  └─ status: (STOPPED) Not enrolled into Fleet
└─ elastic-agent
   ├─ status: (DEGRADED) 1 or more components/units in a degraded state
   ├─ beat/metrics-monitoring
   │  ├─ status: (DEGRADED) DEGRADED
   │  └─ beat/metrics-monitoring
   │     └─ status: (DEGRADED) Elasticsearch request failed: dial tcp 127.0.0.1:9200: connect: connection refused
   ├─ filestream-monitoring
   │  ├─ status: (DEGRADED) DEGRADED
   │  └─ filestream-monitoring
   │     └─ status: (DEGRADED) Elasticsearch request failed: dial tcp 127.0.0.1:9200: connect: connection refused
   ├─ http/metrics-monitoring
   │  ├─ status: (DEGRADED) DEGRADED
   │  └─ http/metrics-monitoring
   │     └─ status: (DEGRADED) Elasticsearch request failed: dial tcp 127.0.0.1:9200: connect: connection refused
   ├─ extensions
   │  ├─ status: StatusOK
   │  └─ extension:health_check/v2
   │     └─ status: StatusOK
   └─ pipeline:logs
      ├─ status: StatusOK
      ├─ exporter:nop
      │  └─ status: StatusOK
      └─ receiver:nop
         └─ status: StatusOK

Related issues

• Closes https://github.com/elastic/ingest-dev/issues/5751

---

This is an automatic backport of pull request #8696 done by [Mergify](https://mergify.com).

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
83.3% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: aa3cbbc

cc @swiatekm