AWS X-Ray Exporter should map rpc values to aws values

[NathanielRN]

Is your feature request related to a problem? Please describe.

Follow up to #5766 where we fixed the logic used to set the namespace on an AWS X-Ray segment created from OTel traces.

The current X-Ray exporter will simply send rpc.* values to the AWS X-Ray backend and not transform them. This resulted in a regression in the OTel Python + AWS X-Ray experience as documented here: aws-observability/aws-otel-lambda#165.

Failure to fix this soon will cause more regression as more languages become spec compliant.

Describe the solution you'd like

Instead of only sending the rpc.service, rpc.method, and rpc.system attributes to the AWS X-Ray backend, we need to map these values to aws.* value that the AWS-XRay backend understands.

Specifically:

• rpc.service -> aws.service
• rpc.method -> aws.operation
• rpc.system is already used in rpc.system has priority to determine aws namespace in awsxrayexporter #5833 to determine the namespace correctly.

Describe alternatives you've considered

The AWS X-Ray backend team could also read rpc.* values in the future, but this would be a much larger effort involving many more teams.

Additional context
See also:

• The AWS SDK Instrumentation specifications which inspired the use of rpc.* values
• The OTel Python PR which used these rpc.* values
• The Downstream ADOT integration tests which caught this change
• The update to the ADOT Test framework to account for these changes
• The E2E Lambda Test which discovered the regression
• The latest template change to reflect the current state of the world caused by the regression
• Our updates to AWS templates that will define where we want to be for OTel <-> AWS X-Ray Backend compatability
  • In the AWS Test Framework for OTel GH Action - Used to Integ Test ADOT Language downstreams
  • In the AWS Lambda Template - Used to compare X-Ray backend traces with expected values

[NathanielRN]

cc @anuraaga @mxiamxia @willarmiros @wangzlei @alolita