samples: updated legacy field in detectintenttexts (#572)

Author: b-loved-dreamer

dialogflow/snippets/src/main/java/com/example/dialogflow/DetectIntentTexts.java

@@ -63,7 +63,11 @@ public static Map<String, QueryResult> detectIntentTexts(
         System.out.format(
             "Detected Intent: %s (confidence: %f)\n",
             queryResult.getIntent().getDisplayName(), queryResult.getIntentDetectionConfidence());
-        System.out.format("Fulfillment Text: '%s'\n", queryResult.getFulfillmentText());
+        System.out.format(
+            "Fulfillment Text: '%s'\n",
+            queryResult.getFulfillmentMessagesCount() > 0
+                ? queryResult.getFulfillmentMessages(0).getText()
+                : "Triggered Default Fallback Intent");
 
         queryResults.put(text, queryResult);
       }