Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1199951
Description of problem:
The API for managing the assication between OS and Media is inconsistent.

You need to add assications in the API under the "media"

PUT /api/v2/media/:id
Update a medium.
...
medium[operatingsystem_ids] False Array Operating System identifier

In the WebUI this is done over Operatings Systems - Installation Media tab. So the other way around.

This is not intuitive and inconsistent for development and troubleshooting API calls.

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

How reproducible:

Steps to Reproduce:
1. Associate OS-Media over API
2. Dis-Associate OS-Media using WebUI
3.

Actual results:
Inconsistent process either over media (API) or over OS (UI)

Expected results:
Consistent process for both API and UI

Additional info: