[8.18] (backport #7754) Set fullnameOverride and validate Otel kube-stack deployment datastreams are being written (metrics, traces)

[mergify]

What does this PR do?

Adds tests to ensure the Helm chart is correctly deployed and data pushed to Elasticsearch:

• Validates metrics collected with the kubeletstats receiver are written to Elasticsearch.
• Deploys a Java application to validate auto-instrumentation works properly and the corresponding traces documents are available in Elasticsearch. As an alternative, I tried to install the OpenTelemetry demo Helm Chart and assert its traces, but it is too heavy (big images, e.g. flagd → 1.2GB) for the testing timeouts.

Why is it important?

Fixes #7381

---

This is an automatic backport of pull request #7754 done by Mergify.

[mergify]

Cherry-pick of 8ec0229 has failed:

On branch mergify/bp/8.18/pr-7754
Your branch is up to date with 'origin/8.18'.

You are currently cherry-picking commit 8ec022980.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   changelog/fragments/1744384247-set-collector's-fullnameOverride-for-edot-kube-stack-values.yaml
	modified:   deploy/helm/edot-collector/kube-stack/managed_otlp/values.yaml
	modified:   deploy/helm/edot-collector/kube-stack/values.yaml
	modified:   testing/integration/kubernetes_agent_standalone_test.go
	new file:   testing/integration/testdata/java_app.yaml

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   testing/integration/otel_helm_test.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[elasticmachine]

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

[elasticmachine]

💔 Build Failed

• Buildkite Build
• Commit: 063f3b7

Failed CI Steps

• check-ci
• Packaging: linux/arm64 tar.gz
• Packaging: Ubuntu arm64 FIPS
• Packaging: Containers linux/arm64

History

cc @rogercoll

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarQube