fix: simplify logic and enable correct recording rule groups for managed prom extension

[bragi92]

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This checklist is used to make sure that common guidelines for a pull request are followed.

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General Guidelines

• Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
• Have you run python scripts/ci/test_index.py -q locally? (pip install wheel==0.30.0 required)
• My extension version conforms to the Extension version schema

For new extensions:

• My extension description/summary conforms to the Extension Summary Guidelines.

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