OTLP Exporter does not set trace_state field

[zacharycmontoya]

Feature Request

Is your feature request related to a problem?

I don't have an urgent issue, but I would like the OTLP exporter to set the span's trace_state field, to have the complete data represented in the OTLP trace.

Describe the solution you'd like:

I would like the OTLP exporter to set the TraceState property when converting the System.Diagnostics.Activity object to its corresponding OpenTelemetry.Proto.Trace.V1.Span object.

Describe alternatives you've considered.

None. The OTLP exporter alone is responsible for exporting the Activity in the form of an OTLP span.

Additional Context

I'm happy to submit a PR to implement this, but I wanted to know if there was a previous decision to omit this, or if this was just missed.

[cijothomas]

Tagging for consideration in 1.5

[cijothomas]

@Yun-Ting Could you check and see if you can take this?

[Yun-Ting]

Hi @zacharycmontoya, please let me know if you are interested in working on this, I can help to review. Thank you.