[otlp-grpc-exporter-base] base package is using trace-specific env vars

[pichlermarc]

What happened?

Steps to Reproduce

Use the gRPC metrics exporter, and set a trace specific environment variable like:

• OTEL_EXPORTER_OTLP_TRACES_CERTIFICATE,
• OTEL_EXPORTER_OTLP_TRACES_CLIENT_KEY,
• OTEL_EXPORTER_OTLP_TRACES_CLIENT_CERTIFICATE,
• OTEL_EXPORTER_OTLP_TRACES_TIMEOUT

Expected Result

Environment variables have no effect on the metrics exporter

Actual Result

Environment variables are used by the metrics exporter.

Additional Details

#3712 (comment)
#3193 (comment)

OpenTelemetry Setup Code

n/a

package.json

n/a

Relevant log output

n/a

[pichlermarc]

I'm working on fixing this.

[pichlermarc]

I didn't have the time to fix this yet - I'm afraid I won't be able to do it for now.