Make product_* values required and add TBD for missing product_section values

What does this MR do and why?

Relates to #342237 (closed)

This MR makes the product_* values in the schema.json as required.

Backfills the existing metric yaml files to use TBD value for th respective teams to update later on.

Fixes specs for metric yamls.

Screenshots or screen recordings

These are strongly recommended to assist reviewers and reduce the time to merge your change.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.