feat(datadogexporter): adds remap_metrics feature gate

[mabdinur]

Description:

Adds a metrics configuration that enables/disables the conversion of OpenTelemetry metrics to Datadog semantics in the Datadog Exporter. This conversion will soon occur in a datadog semantic processor.

Link to tracking Issue: N/A

Testing: Unit tests

̶̶D̶o̶c̶u̶m̶e̶n̶t̶a̶t̶i̶o̶n̶:̶̶̶ O̶n̶c̶e̶ t̶h̶i̶s̶ c̶o̶n̶f̶i̶g̶u̶r̶a̶t̶i̶o̶n̶ i̶s̶ G̶A̶ w̶e̶ w̶i̶l̶l̶ u̶p̶d̶a̶t̶e̶ t̶h̶e̶ d̶o̶c̶s̶ h̶e̶r̶e̶:̶ h̶t̶t̶p̶s̶:̶//d̶o̶c̶s̶.d̶a̶t̶a̶d̶o̶g̶h̶q̶.c̶o̶m̶/o̶p̶e̶n̶t̶e̶l̶e̶m̶e̶t̶r̶y̶/c̶o̶l̶l̶e̶c̶t̶o̶r̶_̶e̶x̶p̶o̶r̶t̶e̶r̶/c̶o̶n̶f̶i̶g̶u̶r̶a̶t̶i̶o̶n̶/

[songy23]

Why does this need to be a config, i.e. when does a customer want to disable it?

If this is only for internal migration to semantic core, we don't need to expose it

[mabdinur]

Why does this need to be a config, i.e. when does a customer want to disable it?

If this is only for internal migration to semantic core, we don't need to expose it

It is internal to semantic-core. Good point we should avoid updating documentation.

[songy23]

Overall I still don't quite understand why we need this PR. I think doing the remapping is mandatory, remapping should never be turned off at any time, otherwise users will have broken user experience. It is an implementation detail how we do the remapping and end users probably wouldn't care

[mabdinur]

Overall I still don't quite understand why we need this PR. I think doing the remapping is mandatory, remapping should never be turned off at any time, otherwise users will have broken user experience. It is an implementation detail how we do the remapping and end users probably wouldn't care

Good point. We need a mechanism to disable remapping in the Exporter so we can handle this logic in a Processor. Remapping will always occur we are just changing where this can happen. End user's will not set this configuration. I will move this change back to a draft state and update this PR to use a feature gate instead.

[mabdinur]

@songy23 How should I test this change?

[songy23]

You can follow the similar in DataDog/datadog-agent#28228 (review) with make otelcontribcol. Run the binary with the feature gate disabled and check no DD conventions are sent to the backend.