Enable Demographics and Interests reports in Universal Analytics - Magento missing code - magento

Question

I am trying too Enable Demographics and Interests reports in Universal Analytics in my Magento site.
I have read through the already existing question on this and it does not answer my problem: Enable Demographics and Interests reports in Universal Analytics
I already have Universal Analytics set for my Magento site, which was done by simply entering my Google Analytics Account Number in the Magento Backend. It has been working fine for the last few months but I now want to Enable Demographics and Interests reports.
Google Analytics tells me "Your Demographics and Interest Reports have been enabled, but your Analytics tracking code does not include the necessary support to show them", and directs me to the following information page: https://support.google.com/analytics/answer/2444872?hl=en&utm_id=ad
It tells me to simply add the following code into the existing tracking code:
ga('require', 'displayfeatures');
I found out that this code should be located at:
app/design/frontend/default/YOURTHEME/template/page/html/head.phtml
However when I open this file, the only code in it is as follows:
<meta http-equiv="Content-Type" content="<?php echo $this->getContentType() ?>" />
<title><?php echo $this->getTitle() ?></title>
<meta name="description" content="<?php echo htmlspecialchars($this->getDescription()) ?>" />
<meta name="keywords" content="<?php echo htmlspecialchars($this->getKeywords()) ?>" />
<meta name="robots" content="<?php echo htmlspecialchars($this->getRobots()) ?>" />
<?php if(Mage::getStoreConfig('milanoconfig/generaloptions/responsive') == 1): ?>
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1" />
<?php endif; ?>
<link rel="icon" href="<?php echo $this->getFaviconFile(); ?>" type="image/x-icon" />
<link rel="shortcut icon" href="<?php echo $this->getFaviconFile(); ?>" type="image/x-icon" />
<?php echo $this->getCssJsHtml() ?>
<?php echo $this->getChildHtml() ?>
<?php echo $this->helper('core/js')->getTranslatorScript() ?>
<?php echo $this->getIncludes() ?>
<!--[if lt IE 7]>
<script type="text/javascript">
//<![CDATA[
var BLANK_URL = '<?php echo $this->helper('core/js')->getJsUrl('blank.html') ?>';
var BLANK_IMG = '<?php echo $this->helper('core/js')->getJsUrl('spacer.gif') ?>';
//]]>
</script>
<![endif]-->
From what I have read, this file should also include the following Google Analytics code, but it doesn't:
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-XXXXXX-XX', 'example.com');
ga('send', 'pageview');
</script>
Does anyone know why this code isn't currently in this file even though my Google Analytics appears to be working fine, after simply adding the Google Analytics Account Number in the Magento Backend?
Does anyone also know what I should now do to Enable the Demographics and Interests reports. Should I simply add this code manually, or is there a reason why this code isn't already in place, maybe Magento is set up differently these days? I use Magento version 1.7.0.2.
Thanks