Steps to reproduce:
1. Login as Admin
2. Create a new iCMA activity or resource.
3. Edit quiz settings and set 'Grade to pass' to 5.0 and save changes.
4. Verify that the Grade to pass is displayed on the quiz view page
5. Navigate back to Admin settings and delete the value from Grade to pass field and save changes.
6. Notice that the Grade to pass retains the previously set value. When 'Grade to pass' is set to empty string, its value should be reset to default 0.0.
7. Go to Admin settings and change the 'Grade to pass' field to have to negative value (e.g., -4) and save changes.
8. Verify that 'Grade to pass' allows negative values.