Not getting proper error message while updating Automate method

[dmetzger57]

For details see: https://bugzilla.redhat.com/show_bug.cgi?id=1824764

Description of problem:

While Updating the method we are not getting a proper error message. It does not tell what is a problem actually.

[Fryguy]

Steps to Reproduce:

1. Add Ansible tower provider in CFME
2. Navigate Automation=>Automate=>Explorer
3. Create Domain, namespace, class, and method with valid input.
4. Try to update method by adding new Input Parameter and use Input Parameter name example "@123", "###" and try to save it.
5. Once we click on save button it gives "Error during 'save': Failed to replace inputs because one or more of the new records could not be saved." error message. The error messages do not tell what is the actual problem with Input Parameter name.

Actual results:
"Error during 'save': Failed to replace inputs because one or more of the new records could not be saved."

Expected results:

The error message should describe the actual problem .