Improve landing page URL for policy compliance checks

[songchen2022]

Changes proposed in this Pull Request:

We should only consider the url for the products with publish status

Reference from this issue

We add this fix to help query only products with publish status.

Detailed test instructions:

1. Create only one product and set it to a publish product.
2. Go through the onboarding steps and confirm that the check "Confirm your store is live and accessible to all users" is passed.

Changelog entry

• Tweak - Retrieve a published product as a landing page URL.

[mikkamp]

Thanks for the change, I can confirm that I get a successful response when creating a private product.

The only suggestion I have is to add a changelog entry in the PR, something like this.

* Tweak - Retrieve a published product as a landing page URL.

[songchen2022]

Thanks for reviewing. I added the changelog as you suggested.