Updated label for Content Type configuration field.

Changed Allowable Methods (Non Doc and Doc) to always be displayed no
matter what the content type mode is.

Changed the isDutiable function to only look at whether a shipment is
domestic or not. Previously it would return dutiable for everything
if the Content Type mode is non document (which causes problems for
domestic shipments in Non Document mode). Fixes #19485

Author: Graham Wharton

app/code/Magento/Dhl/Model/Carrier.php

@@ -1968,8 +1968,6 @@ protected function isDutiable($origCountryId, $destCountryId)
     {
         $this->_checkDomesticStatus($origCountryId, $destCountryId);
 
-        return
-            self::DHL_CONTENT_TYPE_NON_DOC == $this->getConfigData('content_type')
-            || !$this->_isDomestic;
+        return !$this->_isDomestic;
     }
 }

app/code/Magento/Dhl/etc/adminhtml/system.xml

@@ -32,7 +32,8 @@
                     <label>Account Number</label>
                 </field>
                 <field id="content_type" translate="label" type="select" sortOrder="90" showInDefault="1" showInWebsite="1" showInStore="0" canRestore="1">
-                    <label>Content Type</label>
+                    <label>Content Type (Non Domestic)</label>
+                    <comment>Whether to use Documents or NonDocuments service for non domestic shipments. (Shipments within the EU are classed as domestic)</comment>
                     <source_model>Magento\Dhl\Model\Source\Contenttype</source_model>
                 </field>
                 <field id="handling_type" translate="label" type="select" sortOrder="100" showInDefault="1" showInWebsite="1" showInStore="0" canRestore="1">
@@ -81,18 +82,12 @@
                     </depends>
                 </field>
                 <field id="doc_methods" translate="label" type="multiselect" sortOrder="170" showInDefault="1" showInWebsite="1" showInStore="0" canRestore="1">
-                    <label>Allowed Methods</label>
+                    <label>Documents Allowed Methods</label>
                     <source_model>Magento\Dhl\Model\Source\Method\Doc</source_model>
-                    <depends>
-                        <field id="content_type">D</field>
-                    </depends>
                 </field>
                 <field id="nondoc_methods" translate="label" type="multiselect" sortOrder="170" showInDefault="1" showInWebsite="1" showInStore="0" canRestore="1">
-                    <label>Allowed Methods</label>
+                    <label>Non Documents Allowed Methods</label>
                     <source_model>Magento\Dhl\Model\Source\Method\Nondoc</source_model>
-                    <depends>
-                        <field id="content_type">N</field>
-                    </depends>
                 </field>
                 <field id="ready_time" translate="label comment" type="text" sortOrder="180" showInDefault="1" showInWebsite="1" showInStore="0" canRestore="1">
                     <label>Ready time</label>