title: Maximum length zip code validation
body: <p>I am using Magento 2.2 , Zip code validation is not working .`
  Coding part1:</p>
  
  <pre><code>"validate-zip-in": [
              function(value) {
                  return utils.isEmptyNoTrim(value) || /(^\d{6}$)/.test(value);
  
              },
              $.mage.__('Please enter a valid zip code (Ex: 123456).')
          ],
  </code></pre>
  
  <p>Coding part 2:checkout_index_index.xml</p>
  
  <pre><code>     &lt;/item&gt;
                              &lt;item name="validation" xsi:type="array"&gt;
                                                                      &lt;item name="validate-digits" xsi:type="string"&gt;true&lt;/item&gt;
                                                              &lt;/item&gt;  
                              &lt;item name="validation" xsi:type="array"&gt;
                                      &lt;item name="validate-zip-in" xsi:type="string" pattern="[0-9]*" max-length="6"&gt;true&lt;/item&gt;
                                  &lt;item name="zip-range" xsi:type="string"&gt;6&lt;/item&gt;
                              &lt;/item&gt; `
  </code></pre>
  
  <p>But it is not working . I want validate maximum length "6" for India.please reply as soon as possible  </p>