Complete button disabled for already set up Analytics

## Bug Description

This came up while testing https://github.com/google/site-kit-wp/issues/11843.

Here's the scenario:
- User gets the email to connect analytics
- User doesn't click on the link
- User sets up analytics in Google Site kit
- User clicks on link
- User will land on analytics module with the 'Complete' button disabled.

I think we should do a general update on setup module screen to show a message in "Module X setup has already been completed" style.

## Steps to reproduce

1. Setup Site Kit with proactiveUserEngagement feature flag enabled
2. Do not setup Analytics module
3. Subscribe to email reporting
4. Trigger email for the user
5. Notice the 'Set up Analytics' component in the email but don't click on the CTA.
6. Go to SK and set up ANalytics module.
7. Now click on the CTA in the email
8. You will land on analytics module with the 'Complete' button disabled.

## Screenshots

## Additional Context

- PHP Version:
- OS: [e.g. iOS]
- Browser: [e.g. chrome, safari]
- Plugin Version: [e.g. 22]
- Device: [e.g. iPhone6]

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## Acceptance criteria

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## Implementation Brief

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## QA Brief

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