Switch async GCS example to long file (#617)

Author: danaharon

speech/cloud-client/README.md

@@ -46,5 +46,5 @@ You can then run a given `ClassName` via:
 ### Asynchronously transcribe a remote audio file (using the recognize sample)
 ```
     mvn exec:java -Dexec.mainClass=com.example.speech.Recognize \
-    -Dexec.args="asyncrecognize 'gs://cloud-samples-tests/speech/brooklyn.flac'"
+    -Dexec.args="asyncrecognize 'gs://cloud-samples-tests/speech/vr.flac'"
 ```