fix(openfeature): read OTEL_SERVICE_NAME for metrics resource

[sameerank]

What Does This Do

Reads the OTEL_SERVICE_NAME environment variable and sets it as the service.name resource attribute when exporting OTLP metrics from FlagEvalMetrics.

Motivation

The OpenTelemetry SDK's Resource.getDefault() only provides unknown_service:java as the service name. This causes OTLP metrics to be exported with an incorrect service name, making it difficult to identify which service the metrics belong to.

This fix reads OTEL_SERVICE_NAME from the environment (the standard OTel env var) and merges it with the default resource, ensuring metrics are properly attributed to the correct service.

For comparison, the service name in dd-trace-go is set in ddmetric.NewMeterProvider() with priority: DD_SERVICE → DD_TAGS[service] → OTEL_SERVICE_NAME (https://github.com/DataDog/dd-trace-go/blob/fb5394071eff386cdba3517dc9acb9641bac1d7e/ddtrace/opentelemetry/metric/resource.go#L41). Meanwhile Java created its own SdkMeterProvider with just Resource.getDefault().

Additional Notes

• Falls back to Resource.getDefault() if OTEL_SERVICE_NAME is not set
• Uses ConfigHelper.env() for consistent environment variable handling

Contributor Checklist

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• Update the CODEOWNERS file on source file addition, migration, or deletion
• Update public documentation with any new configuration flags or behaviors

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⚠️ Warnings

🚦 53 Pipeline jobs failed

DataDog/apm-reliability/dd-trace-java | Amazon_Linux_2023_amd64.SI94: [test-app-java-alpine]     

🔧 Fix in code (Fix with Cursor).

AssertionError: ❌ There are previous errors in the virtual machine provisioning steps. Check this file in the logs scenario folder: Amazon_Linux_2023_amd64.log

DataDog/apm-reliability/dd-trace-java | Amazon_Linux_2023_amd64.SIM: [test-app-java-alpine]     

🔧 Fix in code (Fix with Cursor).

Exception launching aws provision step remote command. Assertion error during virtual machine provisioning steps.

DataDog/apm-reliability/dd-trace-java | Amazon_Linux_2023_amd64.SIM: [test-app-java]     

🔧 Fix in code (Fix with Cursor).

Error provisioning virtual machine. AssertionError: There are previous errors in the virtual machine provisioning steps. Check the log file: Amazon_Linux_2023_amd64.log

View all 53 failed jobs.

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