9768: Admin dashboard Most Viewed Products Tab only gives default attribute set's products (backport for 2.1)

[RomaKis]

Admin dashboard Most Viewed Products Tab only gives default attribute set's products. Backport from #11725.

Fixed Issues (if relevant)

1. Admin dashboard Most Viewed Products Tab only gives default attribute set's products #9768: Admin dashboard Most Viewed Products Tab only gives default attribute set's products

Manual testing scenarios

1. Login to Customer Account
2. Visited Product "Minerva LumaTech™ V-Tee"
3. Login to magento admin panel
4. Check magento dashboard "Most Viewed Product" grid

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[miguelbalparda]

This seems to differ from the other 2 PRs for this fix. Can you double check it please?

[RomaKis]

@miguelbalparda, changes are different only in unit test, bacause 2.1.x use \PHPUnit_Framework_TestCase class instead of \PHPUnit\Framework\TestCase in 2.2.

[miguelbalparda]

@dmanners can you check this one? All the other backports are already merged, I suspect this one hasn't been picked up yet because of the request for changes but now should be good to go.