Fix import statements and update service name in OpenTelemetry config

[matthewmeyer]

Summary

This pull request updates import statements in samples/python/otel/src/main.py to use relative imports and changes the service name used in the OpenTelemetry configuration. These changes help ensure the code works correctly as a module and improve service naming consistency.

Import improvements:

• Changed all import statements from absolute to relative imports to ensure proper module resolution when running the script as part of a package.

Configuration update:

• Updated the service name in the configure_otel_providers call from "quickstart_agent" to "otel_quickstart_agent" for improved clarity and consistency.

Testing

Ran locally and verified