Tag Code Suggestions E2E tests as smoke tests

What does this MR do and why?

Makes the 2 CS E2E tests smoke tests. The tests have been passing consistently and the most recent failure was due to a bug (see #430866 (comment 1636129520)).

Also replaces a comment about setup with a link to setup documentation.

How to set up and validate locally

It can only be run against Staging or Prod. See instructions in !131604 (merged)

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MR acceptance checklist

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