title: Dart 2.3 for, if and spread support warning message regarding versions
body: <p>I am getting the warning message '<strong>The for, if and spread elements were not supported until version 2.2.2, but this code is required to be able to run on earlier versions</strong>' but the code </p>
  
  <pre><code>Column(   crossAxisAlignment: CrossAxisAlignment.start,
              children: &lt;Widget&gt;[
                if (document['propertyid'] == '1') Text('jjj'),
                GestureDetector(
                  onTap: () {
                    Navigator.push(
                        context,
                        MaterialPageRoute(
                            builder: (context) =&gt;
                                PropertyDetails(document['propertyid'])));
                  },
                  child: Text(document['propertyname'],
                      style: TextStyle(
                          color: Colors.blue,
                          fontStyle: FontStyle.italic,
                          fontWeight: FontWeight
                              .w500) //Theme.of(context).textTheme.title,
                      ),
                ),
              ],
    ),
  </code></pre>
  
  <p>works as expected. The minSDKVersion etc is 28. Why does it think I want to be able to run this code on any earlier version? What do I need to change to a later version?</p>