[AWS S3] Test Failed due to pagebuilder page loading issue

[dhaecker]

Adding pagebuilder file upload spinner to loadingMaskLocators

Description

Fixed Issues (if relevant)

1. https://jira.corp.magento.com/browse/B2B-2098

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/verification tests (if applicable)
• [ ] All automated tests passed successfully (all builds on Travis CI are green)
• [ ] Changes to Framework doesn't have backward incompatible changes for tests or have related Pull Request with fixes to tests