Parse default value in Service Dialog

[jntullo]

Ok @romanblanco, let's try this again 😛

re-opened version of #15878

When serializing the dialog, it should return an array of values rather than a string if force_multi_value is true

Tested this out via the API:
GET api/service_dialogs/:id
and the result seems to be as expected, as you can see from the default_values in the response:

{  
   "href":"http://localhost:3000/api/service_dialogs/10000000000001",
   "id":"10000000000001",
   "buttons":"submit,cancel",
   "created_at":"2017-11-03T18:09:55Z",
   "updated_at":"2017-11-03T18:09:55Z",
   "label":"azure-single-vm-from-user-image",
   "content":[  
      {  
         "href":"http://localhost:3000/api/service_dialogs/10000000000001",
          ... 
         "dialog_tabs":[  
            {  
               "id":"10000000000011",
                 ...
               "dialog_groups":[  
                  {  
                     "id":"10000000000016",
                      ...
                     "dialog_fields":[  
                        {  
                           "href":"http://localhost:3000/api/service_dialogs/10000000000091",
                           "id":"10000000000091",
                           "name":"tenant_name",
                           "description":"Tenant where the stack will be deployed",
                           "data_type":"string",
                           "display":"edit",
                           "display_method_options":{  

                           },
                           "required":false,
                           "required_method_options":{  

                           },
                           "default_value":[  
                              "a",
                              "b"
                           ],
                       ....
            }
         ]
      }
   ],
   "actions":[  
    ...
   ]
}

@miq-bot assign @gmcculloug
@miq add_label enhancement, services

[gmcculloug]

cc @eclarizio

[eclarizio]

Just a small change to the spec and I think this looks good 👍

[eclarizio]

Minor change, but I think this should be hard-coded to %w(one two). There's really no way the .split method is going to change, but I feel like matching the test expected output with what the code is actually doing doesn't really set the expectation correctly.

[miq-bot]

Checked commit jntullo@a613395 with ruby 2.3.3, rubocop 0.47.1, haml-lint 0.20.0, and yamllint 1.10.0
2 files checked, 0 offenses detected
Everything looks fine. 🍰