title: Cordova CLI - not updating config.xml
body: <p>I have used the Cordova CLI 6.5.0 for the past 1-2 years, and it's acted normally.  We are upgrading our main app to <code>android@8.0.0</code>, which required a Cordova CLI upgrade.  In using Cordova CLI 9.0.0, I'm noticing that many things are no longer updating the config.xml file:</p>
  
  <ul>
  <li>platform adds - no longer see <code>&lt;engine&gt;</code> elements</li>
  <li>plugin adds - not adding <code>&lt;plugin&gt;</code> elements</li>
  </ul>
  
  <p>I am making sure <code>--save</code> is used in the commands (which I gather is not even required anymore).  When I run a <code>cordova platform list</code> or <code>cordova plugin list</code> I see the expected platforms/plugins.  I also see that the package.json is used more heavily now.  However, the plugin/platform versions are not in the package.json so I can't imagine that's a complete replacement?</p>
  
  <p>Lastly, some additional things I've tried:</p>
  
  <ul>
  <li>running <code>cordova platform android save</code></li>
  <li>running <code>cordova clean</code> and <code>cordova prepare</code></li>
  <li>adding and removing the platform (and ditching the related directories)</li>
  <li>Running an actual build (which works fine)</li>
  </ul>
  
  <p>Is this "normal"?  Do these newer cordova versions not leverage the config.xml as regularly now?</p>