fix(samples): end stream before destroying it (#611)

I've been getting this error until I put call of end() for the stream before destroying it.
`API request error 14 UNAVAILABLE: 408:Request Timeout`

Co-authored-by: Alexander Fenster <[email protected]>

Author: Wirnex

speech/infiniteStreaming.js

@@ -190,6 +190,7 @@ function infiniteStream(
 
   function restartStream() {
     if (recognizeStream) {
+      recognizeStream.end();
       recognizeStream.removeListener('data', speechCallback);
       recognizeStream = null;
     }