Adding telemetry to streamed agent responses

[fredjoonpark]

Adding telemetry to streamed agent responses

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Describe your changes

This change configures OTEL tracing with span attributes for collecting telemetry data from agents. This allows for integration with any OTEL-compatible collector for implementing observability when working with Bedrock agent samples.

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Issue ticket number and link

• Issue Amazon Bedrock Agent Samples - Adding OTEL tracing to bedrock_agent_helper.py #138

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All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Are you uploading a dataset?
• Have you added contributions to RELEASE NOTES?

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• Does this implementation use the helper functions src/utils/*. List them here:

1. bedrock_agent_helper.py