Put CS E2E test back in smoke suite

What does this MR do and why?

Puts the Code Suggestions e2e test back in the smoke suite after some failures that couldn't be reproduced.

See #431317 (closed)

How to set up and validate locally

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

The dashboard shows their current status.

MR acceptance checklist

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