title: text justify is not working correctly with RichText
body: <p>I am using <code>RichText</code> and in this
  text justify is not working correctly with <code>RichText</code> when using any of text span with style <code>decoration: TextDecoration.underline</code></p>
  <pre><code>RichText(
            softWrap: true,
            textAlign: TextAlign.justify,
            text: TextSpan(
              style: TextStyle(
                color: Colors.black,
                fontWeight: FontWeight.w500,
                fontSize: 16.0,
              ),
              children: getSpan(),
            ),
          )
  </code></pre>
  <pre><code>List&lt;TextSpan&gt; getSpan() {
      List&lt;TextSpan&gt; spans = List&lt;TextSpan&gt;();
      spans.add(TextSpan(
        text:
        &quot;And thus We made them rise &quot;,
      ));
      spans.add(
        TextSpan(
            text: &quot; they &quot;,
            style: TextStyle(
               decoration: TextDecoration.underline,
            ),
            recognizer: TapGestureRecognizer()
              ..onTap = () {
                print(&quot;click on me&quot;);
              }),
      );
      spans.add(TextSpan(
        text:
        &quot; And thus We made them rise &quot;,
      ));
      return spans;
    }
  </code></pre>
  <p><a href="https://i.stack.imgur.com/qHMMV.png" rel="noreferrer"><img src="https://i.stack.imgur.com/qHMMV.png" alt="See the restul" /></a></p>