fix build

Change-Id: I5680c6001dd27ae2ae85ab114ef82021229c8c9c
diff --git a/Android.mk b/Android.mk
index 802574c..73c3227 100644
--- a/Android.mk
+++ b/Android.mk
@@ -20,7 +20,7 @@
 
 LOCAL_SRC_FILES := $(call all-java-files-under, AccessCheck/src)
 
-#LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_TAGS := optional
 
 LOCAL_MODULE := accessibilityvalidator