SEAndroid: Allow mediaserver to access media files for testing

Display APT test apps require access to "/data/display-test/media/*"
location for test automation.

Change-Id: If8b17594d129df119707d8212187c3c0e48ddb8e
diff --git a/test/file_contexts b/test/file_contexts
index 95f9649..f41cc3c 100755
--- a/test/file_contexts
+++ b/test/file_contexts
@@ -57,3 +57,6 @@
 /system/bin/test-fake-ap                        u:object_r:location_exec:s0
 /system/bin/loc_api_app                         u:object_r:location_exec:s0
 /system/bin/test_loc_api_client                 u:object_r:location_exec:s0
+
+#Context for mediaserver
+/data/display-tests/media(/.*)?                 u:object_r:display_test_media_file:s0