sorry for the delayed response. We do have built in support for that though I'm not sure which version it was added in.
To use it you would change this in layout.master:
<portal:AnalyticsAsyncTopScript ID="analyticsTop" runat="server" />
<portal:AnalyticsAsyncTopScript ID="analyticsTop" runat="server" UseUniversal="true" EnableDisplayFeatures="true" />
if you find that does not work in version 18.104.22.168, I think you can still work around it because of the way the google script works async. You could just add your own below the control I just mentioned something like this:
<script> ga('require', 'displayfeatures'); </script>