fix method reference

Author: rpanackal

orchestration/src/main/java/com/sap/ai/sdk/orchestration/OrchestrationChatResponse.java

@@ -48,7 +48,7 @@ public String getContent() throws OrchestrationOutputFilterException {
           Optional.of(getOriginalResponse().getModuleResults().getOutputFiltering())
               .map(outputFiltering -> (Map<String, Object>) outputFiltering.getData())
               .map(data -> (List<Map<String, Object>>) data.get("choices"))
-              .map(List::getFirst)
+              .map(choices -> choices.get(0))
               .orElseGet(Map::of);
 
       throw new OrchestrationOutputFilterException(