Camera ITS: Fix test_multi_camera failed

In case a physical camera that contains only DEPTH information is
included in a logical camera, evaluating the DEPTH camera is
inappropriate because depth only camera doesn't have
backward-compatible capability.
However, this test does not check backward-compatible capability,
and the test fails due to unmatched yuv size.
To avoid the test failed, adding check for backward-compatible
capability is necessary.

Bug: 154668736
Test: CTS build and execution

Change-Id: Id5a057f1cdd4fd318c476bd569cbfee5e2321619
diff --git a/apps/CameraITS/tests/scene1/test_multi_camera_match.py b/apps/CameraITS/tests/scene1/test_multi_camera_match.py
index 311a36f..2429837 100644
--- a/apps/CameraITS/tests/scene1/test_multi_camera_match.py
+++ b/apps/CameraITS/tests/scene1/test_multi_camera_match.py
@@ -41,6 +41,7 @@
         for i in ids:
             physical_props = cam.get_camera_properties_by_id(i)
             its.caps.skip_unless(not its.caps.mono_camera(physical_props))
+            its.caps.skip_unless(its.caps.backward_compatible(physical_props))
             yuv_sizes[i] = its.objects.get_available_output_sizes(
                     'yuv', physical_props)
             if i == ids[0]:  # get_available_output_sizes returns sorted list