Before in CheckPermissionBeforeUpdate, access was verified for updated
permissions. Now access is verified for existing permissions.
Refactored guardian tests to cover more test cases for org admin, editor
and viewer roles
If a dashboard inherits permissions from a folder, don't allow same permission to be added
to the dashboard with a lower permission.
Add backend validation so that you cannot add same permission to folder/dashboard, for example
same user/team with different permissions