ENGCOM-4786: PUT /V1/products/:sku/media/:entryId does not change the file #22424

 - Merge Pull Request #22424 from Nazar65/magento2:issue-22402
 - Merged commits:
   1. 9205c6f

Author: magento-engcom-team

app/code/Magento/Catalog/Model/Product/Gallery/GalleryManagement.php

@@ -105,7 +105,10 @@ public function update($sku, ProductAttributeMediaGalleryEntryInterface $entry)
 
             if ($existingEntry->getId() == $entry->getId()) {
                 $found = true;
-                if ($entry->getFile()) {
+
+                $file = $entry->getContent();
+
+                if ($file && $file->getBase64EncodedData() || $entry->getFile()) {
                     $entry->setId(null);
                 }
                 $existingMediaGalleryEntries[$key] = $entry;