call sendStatus only when there is a result

bug: 8964011
Change-Id: Ib0d368992c65f5c281076cde68c651035546a24d
diff --git a/suite/pts/deviceTests/ptsutil/src/com/android/pts/util/DeviceReportLog.java b/suite/pts/deviceTests/ptsutil/src/com/android/pts/util/DeviceReportLog.java
index 43e93d3..80f3850 100644
--- a/suite/pts/deviceTests/ptsutil/src/com/android/pts/util/DeviceReportLog.java
+++ b/suite/pts/deviceTests/ptsutil/src/com/android/pts/util/DeviceReportLog.java
@@ -38,8 +38,11 @@
 
     public void deliverReportToHost(Instrumentation instrumentation) {
         Log.i(TAG, "deliverReportToHost");
-        Bundle output = new Bundle();
-        output.putString(PTS_RESULT, generateReport());
-        instrumentation.sendStatus(INST_STATUS_IN_PROGRESS, output);
+        String report = generateReport();
+        if (!report.equals("")) {
+            Bundle output = new Bundle();
+            output.putString(PTS_RESULT, report);
+            instrumentation.sendStatus(INST_STATUS_IN_PROGRESS, output);
+        }
     }
 }