Add runner logs

Author: sakthivelmanii

google-cloud-spanner/src/main/java/com/google/cloud/spanner/GrpcStreamIterator.java

@@ -165,6 +165,7 @@ public void onCompleted() {
 
     @Override
     public void onError(SpannerException e) {
+      System.out.println("Error " + e.getMessage() +  " " + e.getErrorCode());
       if (statement != null) {
         if (logger.isLoggable(Level.FINEST)) {
           // Include parameter values if logging level is set to FINEST or higher.