Fixed filtered attribute translation in the AWS X-Ray exporter.

[jefchien]

Description: In the AWS X-Ray exporter, non-string attribute values were showing up as empty strings. Imported the AttributeValueToString function from protospan_translation.go and used it to perform the translation.

Link to tracking Issue: aws-observability/aws-otel-collector#518

Testing: Tested with aws-otel-test-framework. Added TestSpanWithFilteredAttributes test to http_test.go to check each of the types.

[anuraaga]

Thanks for looking into this @jefchien. It looks like there is a fundamental problem with the attribute filtering - it should still use attributes, not strings, since XRay supports non-string attributes. We convert here

https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/exporter/awsxrayexporter/translator/segment.go#L327

But currently only do so for resources attributes - the same should be done for span attributes. Would you be able to make the change so the attribute filtering happens on attributes instead of string map?

[jefchien]

So, instead of converting the pdata.AttributeValues to strings in http.go, the filtered span attributes should be passed in full until they reach the metadata or are otherwise used. That makes sense. Thanks for the clarification!

[anuraaga]

Thanks!