Description of problem:
When setting the Synced Content in the hostgroup, the information is not persistent for visualization, and by that I mean, if we reopen the hostgroup, the content sync is still empty. However, if we create a new server and use the hostgroup, we can see the content synced information properly.

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

How reproducible:
100%

Steps to Reproduce:
1. Install satellite
2. Sync repos + kickstart
3. Create a hostgroup and set the Synced Content

Actual results:
If you reopen the hostgroup, the Synced Content is empty

Expected results:
If you reopen the hostgroup, the Synced Content should be present

Additional info:
This was working on 6.13