ITS: fix sc-dev unittest errors

bug: 179702327
Change-Id: Ib1f4eaf7518dd83555cd593b76c3da88e27bf074
diff --git a/apps/CameraITS2.0/utils/target_exposure_utils.py b/apps/CameraITS2.0/utils/target_exposure_utils.py
index a31f951..04c5f2e 100644
--- a/apps/CameraITS2.0/utils/target_exposure_utils.py
+++ b/apps/CameraITS2.0/utils/target_exposure_utils.py
@@ -17,6 +17,8 @@
 import logging
 import os
 import sys
+import unittest
+
 import capture_request_utils
 import image_processing_utils
 import its_session_utils
@@ -245,3 +247,7 @@
 
   # Compute the exposure value that would result in a luma of 0.5.
   return sens * exp_time * 0.5 / luma_mean[0]
+
+
+if __name__ == '__main__':
+  unittest.main()