Set list to [0] if it is empty

Empty list values are triggering 400 Bad Request for JSON. Setting it to
[0] if empty should resolve the issue.

BUG=None
TEST=Tested on a local setup

Change-Id: I4c4c3c7051672b7155efd15685445829285706dd
Reviewed-on: https://chromium-review.googlesource.com/604724
Commit-Ready: Denis Tosic <dtosic@chromium.org>
Tested-by: Harpreet Grewal <harpreet@chromium.org>
Reviewed-by: Harpreet Grewal <harpreet@chromium.org>
Reviewed-by: Denis Tosic <dtosic@chromium.org>
diff --git a/server/cros/cfm_jmidata_v3_helper.py b/server/cros/cfm_jmidata_v3_helper.py
index bd32859..3c38d4e 100644
--- a/server/cros/cfm_jmidata_v3_helper.py
+++ b/server/cros/cfm_jmidata_v3_helper.py
@@ -74,6 +74,8 @@
                                  jmi_obj[key] == 'true')):
                             jmi_obj[key] = 1 if jmi_obj[key] == 'true' else 0
                         data_list.append(jmi_obj[key])
+        if not data_list:
+            data_list = [0]
         return data_list
 
     def GetAudioReceivedBytesList(self):
@@ -198,6 +200,8 @@
                                 frame_rate != 0:
                             video_streams += 1
             num_video_streams.append(video_streams)
+        if not num_video_streams:
+            num_video_streams = [0]
         return num_video_streams
 
     def GetCpuUsageList(self, cpu_type):