Move base64 to test code

Change-Id: I0cda5d8a559a2d60250c1d8a8ee6f69509515214
diff --git a/Android.mk b/Android.mk
index e32cc7a..ee8cce7 100644
--- a/Android.mk
+++ b/Android.mk
@@ -18,6 +18,8 @@
 include $(CLEAR_VARS)
 
 build_path := $(LOCAL_PATH)/build
+include $(build_path)/Android.common.mk
+
 include $(build_path)/Android.libart.mk
 include $(build_path)/Android.test.mk
 include $(build_path)/Android.aexec.mk