Revert "Remove horizon job due to the unstable UI tests"
and set job to non-voting

This reverts commit fb36d4287813ce2553b256c0d9d547d435c30444.

Change-Id: Ib780b471ebfaa2125bbe842b3660e6e7bedcf1c9
Merge "Revert "Remove horizon job due to the unstable UI tests" and set job to non-voting"