[discuss] opt-in to new HTTP semantic conventions

[david-luna]

@opentelemetry/instrumentation-http added the possibility to opt-in to the stable HTTP semantic conventions for span attributes
ref: open-telemetry/opentelemetry-js#4978

As we can see in the announcement there is a env var to opt-in for the new stable attribs (OTEL_SEMCONV_STABILITY_OPT_IN).

Should the distro have a default configuration value of http which tells the instrumentation to emit only stable attributes or should it keep it as is?

[david-luna]

discussed in https://github.com/elastic/apm-nodejs-dev/issues/57 and decided:

• EDOT should behave like upstream, so we won't change defaults
• make sure we document this and encourage users to opt-in