ENGCOM-4751: Fixed 'Please specify the admin custom URL' error on app:config:import CLI command #22281

 - Merge Pull Request #22281 from davidalger/magento2:github-15090
 - Merged commits:
   1. 8434d74
   2. e340978

Author: magento-engcom-team

app/code/Magento/Config/Model/Config/Backend/Admin/Usecustom.php

@@ -10,6 +10,8 @@
 namespace Magento\Config\Model\Config\Backend\Admin;
 
 /**
+ * Process custom admin url during configuration value save process.
+ *
  * @api
  * @since 100.0.2
  */