MC-41854: Page builder gallery load issue

Author: nikita-shcherbatykh

app/code/Magento/Cms/Block/Adminhtml/Wysiwyg/Images/Tree.php

@@ -5,8 +5,6 @@
  */
 namespace Magento\Cms\Block\Adminhtml\Wysiwyg\Images;
 
-use Magento\Framework\Filesystem;
-
 /**
  * Directory tree renderer for Cms Wysiwyg Images
  *
@@ -34,33 +32,25 @@ class Tree extends \Magento\Backend\Block\Template
      */
     private $serializer;
 
-    /**
-     * @var Filesystem
-     */
-    private $fileSystem;
-
     /**
      * @param \Magento\Backend\Block\Template\Context $context
      * @param \Magento\Cms\Helper\Wysiwyg\Images $cmsWysiwygImages
      * @param \Magento\Framework\Registry $registry
      * @param array $data
-     * @param Filesystem $fileSystem
      * @param \Magento\Framework\Serialize\Serializer\Json|null $serializer
      * @throws \RuntimeException
      */
     public function __construct(
         \Magento\Backend\Block\Template\Context $context,
         \Magento\Cms\Helper\Wysiwyg\Images $cmsWysiwygImages,
         \Magento\Framework\Registry $registry,
-        Filesystem $fileSystem,
         array $data = [],
         \Magento\Framework\Serialize\Serializer\Json $serializer = null
     ) {
         $this->_coreRegistry = $registry;
         $this->_cmsWysiwygImages = $cmsWysiwygImages;
         $this->serializer = $serializer ?: \Magento\Framework\App\ObjectManager::getInstance()
             ->get(\Magento\Framework\Serialize\Serializer\Json::class);
-        $this->fileSystem = $fileSystem;
         parent::__construct($context, $data);
     }
 
@@ -111,7 +101,7 @@ private function getFilteredNestedDirectories(string $storageRoot, string $fileN
         $result = [];
         $pathList = $this->getMediaDirectory()->read($fileName);
         foreach ($pathList as $directoryPath) {
-            $directory = $this->fileSystem->getDirectoryReadByPath($storageRoot . $directoryPath);
+            $directory = $this->_filesystem->getDirectoryReadByPath($storageRoot . $directoryPath);
             if (!$directory->isDirectory()) {
                 continue;
             }