Turn on Proguard by default for user/userdebug builds.
diff --git a/core/java.mk b/core/java.mk
index fc28abf..bc81eae 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -218,6 +218,9 @@
 endif # test package
 
 LOCAL_PROGUARD_ENABLED:=$(strip $(LOCAL_PROGUARD_ENABLED))
+ifeq ($(LOCAL_PROGUARD_ENABLED),disabled)
+    LOCAL_PROGUARD_ENABLED :=
+endif
 ifneq ($(LOCAL_PROGUARD_ENABLED),)
 ifeq ($(LOCAL_PROGUARD_ENABLED),full)
     # full