CameraITS: ensure min yuv format is landscape for tests

Change-Id: I73c9bfa0087e574a299dc2337a190536fb622f38
diff --git a/apps/CameraITS/tests/scene1/test_linearity.py b/apps/CameraITS/tests/scene1/test_linearity.py
index 9e9f1cc..9de1af3 100644
--- a/apps/CameraITS/tests/scene1/test_linearity.py
+++ b/apps/CameraITS/tests/scene1/test_linearity.py
@@ -51,10 +51,12 @@
                              its.caps.per_frame_control(props))
 
         debug = its.caps.debug_mode()
+        largest_yuv = its.objects.get_largest_yuv_format(props)
         if debug:
-            fmt = its.objects.get_largest_yuv_format(props)
+            fmt = largest_yuv
         else:
-            fmt = its.objects.get_smallest_yuv_format(props)
+            match_ar = (largest_yuv['width'], largest_yuv['height'])
+            fmt = its.objects.get_smallest_yuv_format(props, match_ar=match_ar)
 
         e,s = its.target.get_target_exposure_combos(cam)["midSensitivity"]
         s /= 2