controller/pull: only re-request reviews for non-approval reviews
controller/pull: only re-request reviews for non-approval reviews

Re-requesting reviews from reviewers who already gave approvals wastes a
lot of reviewing time.

pyokagan/CanIHasReview,CanIHasReview/CanIHasReview,pyokagan/CanIHasReview,CanIHasReview/CanIHasReview