Add an initial native test on host environment

This CL adds an initial native test that runs on host
environment, from which we can extend the coverage of native
test.

BUG: 13754552
Change-Id: I0af9d1b5dd049c83b955f5b05add4b39f3cfcc6c
diff --git a/native/jni/Android.mk b/native/jni/Android.mk
index c1372bd..5c117ce 100644
--- a/native/jni/Android.mk
+++ b/native/jni/Android.mk
@@ -87,6 +87,8 @@
 LOCAL_LDFLAGS += -ldl
 
 include $(BUILD_SHARED_LIBRARY)
-
 #################### Clean up the tmp vars
 include $(LOCAL_PATH)/CleanupNativeFileList.mk
+
+#################### Unit test on host environment
+include $(LOCAL_PATH)/HostUnitTests.mk