The logic hiding the next arrow on the change list view was incorrect
when there was a full page of results, but no more to dipslay.
The API includes an attribute _more_changes on the last item of the
array to let the client know whether or not there should be another
page. This change uses _more_changes instead of comparing to
_changesPerPage to take this edge case into account.
Bug: Issue 5622
Change-Id: I17dba2c807d152485494405fb412a502ba666df6
4491ff19a4