libion: initial unit tests

Change-Id: I5502b71d0c7c24d7fd59e4880033657f840b341a
diff --git a/libion/Android.mk b/libion/Android.mk
index 42e6f07..e5d495b 100644
--- a/libion/Android.mk
+++ b/libion/Android.mk
@@ -16,3 +16,5 @@
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include $(LOCAL_PATH)/kernel-headers
 LOCAL_SHARED_LIBRARIES := liblog
 include $(BUILD_EXECUTABLE)
+
+include $(call first-makefiles-under,$(LOCAL_PATH))