[UTR Logging] Fix request count self metric when otel_logging and otlp_exporter are enabled

[XuechunHou]

Description

Updated confgenerator code to generate correct agent.googleapis.com/agent/request_count metric.

Related issue

b/492128849

How has this been tested?

Checklist:

• Unit tests
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  • Unit tests have been added/modified and passed for this PR.
• Integration tests
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  • Integration tests have been added/modified and passed for this PR.
• Documentation
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  • This PR introduces user visible changes and the corresponding documentation change has been made.
• Minor version bump
  • This PR introduces no new features.
  • This PR introduces new features, and there is a separate PR to bump the minor version since the last release already.
  • This PR bumps the version.