feat(shared-metrics): Set up Glean frontend metrics for Churn intervention

[xlisachan]

Because

• we want to set up Glean frontend metrics for churn intervention

This pull request

• Create yaml file for Glean frontend
• Update pipeline
• Update glean in payments-metrics
• Data review

Issue that this pull request solves

Closes: (issue number)

Checklist

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• My commit is GPG signed.
• If applicable, I have modified or added tests which pass locally.