Update ElasticsearchProviderResourceMetadataCollectionFactory.php

by default the elasticsearch is not false but null so it will create confusion with indices and try to check the index as the shortName.
But the shortName by default is the model class and it is not true for every cases , even if the index is different of the class and create an issue

Author: rapaelector

src/Elasticsearch/Metadata/Resource/Factory/ElasticsearchProviderResourceMetadataCollectionFactory.php

@@ -82,7 +82,7 @@ public function create(string $resourceClass): ResourceMetadataCollection
 
     private function hasIndices(Operation $operation): bool
     {
-        if (false === $operation->getElasticsearch()) {
+        if (false === $operation->getElasticsearch() || null === $operation->getElasticsearch()) {
             return false;
         }