Added some more Split density tests

Change-Id: I3b83515f1240e713bbcff5385cf054bba693f297
diff --git a/libs/androidfw/tests/Android.mk b/libs/androidfw/tests/Android.mk
index 5808d20..1344dd9 100644
--- a/libs/androidfw/tests/Android.mk
+++ b/libs/androidfw/tests/Android.mk
@@ -26,6 +26,7 @@
     Idmap_test.cpp \
     ResTable_test.cpp \
     Split_test.cpp \
+    TestHelpers.cpp \
     Theme_test.cpp \
     TypeWrappers_test.cpp \
     ZipUtils_test.cpp