Description of problem:
When the import_only flag is enabled on a Content View, there is no option to disable it in the Satellite UI.

Version-Release number of selected component (if applicable):
6.11

How reproducible:
Fully

Steps to Reproduce:
1. Navigate to Content -> Content Views
2. Click on 'Create content view', tick the 'Import only' checkbox.
2. Click 'Create content view.

Actual results:

• After the content view is created, view the 'Details' tab and note the toggle button next to 'Import only' is disabled.
• The only way to get around this seems to be deleting the CV and creating again with 'Import only' unchecked.

Expected results:

• Provide option to disable 'Import only' on content views.

Additional info:

• User is trying to disable the import_only option from CVs to test publishing but 'Import only' option in the UI greyed out.
• Disabling import_only can be done using foreman-rake.
  ~~~

1. foreman-rake --tasks | grep katello:set
   rake katello:set_content_view_import_only

1. foreman-rake katello:set_content_view_import_only ID=<content view id> VALUE=false
   ~~~