Fix broken FF rollout issue

What does this MR do and why?

This MR fixes a couple of issues on the Feature Flag Rollout Issue by the recent change.

• There is an empty line in the middle of checkboxes. This is currently causing markdown rendering issue. E.g. #340380 (closed)
• Verification step on specific/partial rollout must come before the Incremental Rollout, because Incremental Rollout is technically a part of global rollout.
• There is a misleading checkboxes on the actor-specific rollout !71254 (comment 690061924)

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