Description of problem:
Trying to update content view information (content view id) for existing content view filter entity and constantly getting 404 error.

For example:

PUT: https://your_server/katello/api/v2/content_view_filters/16
     {"content_view_id":100}

Error:
Received HTTP 404 response: {"displayMessage":"Couldn't find ContentViewFilter with id=16","errors":["Couldn't find ContentViewFilter with id=16"]}

Everything works fine in case I will try to update another field (e.g. 'type')

Version-Release number of selected component (if applicable):
6.1.6

How reproducible:
Always

Steps to Reproduce:
1. Create couple of content view entries
2. Create content view filter for one content view
3. Try to update content view filter and assign another content view for it

Actual results:
404 error is raised

Expected results:
Update procedure passed successfully
or
In case that scenario is wrong due any reasons corresponding documentation entries for API should be changed and proper error message should be generated and displayed

Additional info: