Improve the pgBackRest repo host RBAC test

[tjmoore4]

Checklist:

• Have you added an explanation of what your changes do and why you'd like them to be included?
• Have you updated or added documentation for the change, as applicable?
• Have you tested your changes on all related environments with successful results, as applicable?
  • Have you added automated tests?

Type of Changes:

• New feature
• Bug fix
• Documentation
• Testing enhancement
• Other

What is the new behavior (if this is a feature change)?

• Breaking change (fix or feature that would cause existing functionality to change)
  This commit updates the pgBackRest repo host RBAC test to ensure desired annotations are passed as expected.

Other Information: