Description of problem:

We forgot to add the ability to add/remove objects from PM Proxy Preference list in Power Management tab in Edit Host, so if user for example needs to add "Other DC" to the list, he has to do that in REST API.

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

oVirt 3.6.0 RC

How reproducible:

100%

Steps to Reproduce:
1. Open New Host dialog, go to Power Management tab, enable power managmement and show Advanced Parameters
2. The order of objects in Power Management Proxy Preference list can be changed, but add/removing objects is not possible

Actual results:

Adding/removing objects from Power Management Proxy Preference list is not possible

Expected results:

Adding/removing objects from Power Management Proxy Preference list is possible,
allowed objects in the list are specified in FenceProxySourceType enum.


Additional info: