fix(gateway-addons-helm): enable kubernetesAttributes preset for OpenTelemetry Collector

[Nexusrex18]

What this PR fixes

When deploying the gateway-addons-helm chart with only OpenTelemetry Collector enabled (opentelemetry-collector.enabled: true), the collector pod logs RBAC errors because no ClusterRole/ClusterRoleBinding is created for the otel-collector service account.

Error example from issue #7726:
pods is forbidden: User "system:serviceaccount:gateway-api-resources:otel-collector" cannot list resource "pods" at the cluster scope replicasets.apps is forbidden: User "system:serviceaccount:gateway-api-resources:otel-collector" cannot list resource "replicasets" namespaces "kube-system" is forbidden: User "system:serviceaccount:gateway-api-resources:otel-collector" cannot list resource "namespaces"

Root cause

The OpenTelemetry Collector subchart only creates RBAC when either:

1. clusterRole.create: true OR
2. One of the presets is enabled (like kubernetesAttributes.enabled: true)

The gateway-addons-helm chart's default values don't enable any presets, so when users enable only the collector, they get no RBAC.

Solution

Enable the kubernetesAttributes preset by default in the OpenTelemetry Collector configuration. This preset provides exactly the permissions shown in the error logs:

• pods and namespaces (for Kubernetes discovery)
• replicasets (for pod owner references)

The change adds 5 lines after fullnameOverride: otel-collector in values.yaml:

  # Enable kubernetesAttributes preset to ensure RBAC is created
  # when the collector is enabled (required for k8s discovery)
  presets:
    kubernetesAttributes:
      enabled: true

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.51%. Comparing base (895a853) to head (55d6aaf).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7791      +/-   ##
==========================================
- Coverage   72.52%   72.51%   -0.01%     
==========================================
  Files         235      235              
  Lines       34859    34859              
==========================================
- Hits        25280    25279       -1     
- Misses       7772     7774       +2     
+ Partials     1807     1806       -1     

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[zirain]

please run make -k gen-check locally and commit the changes to make CI happy.

[Nexusrex18]

@zirain done the changes