Respect DISABLE_PROGUARD

The flag is only used by unbundled build currently.

Change-Id: I8e9bab69dd7accae52ec8cdd627fc4e24178a790
diff --git a/core/package.mk b/core/package.mk
index 2012351..36fb54c 100644
--- a/core/package.mk
+++ b/core/package.mk
@@ -130,11 +130,13 @@
 
 LOCAL_PROGUARD_ENABLED:=$(strip $(LOCAL_PROGUARD_ENABLED))
 ifndef LOCAL_PROGUARD_ENABLED
+ifneq ($(DISABLE_PROGUARD),true)
 ifneq ($(filter user userdebug, $(TARGET_BUILD_VARIANT)),)
     # turn on Proguard by default for user & userdebug build
     LOCAL_PROGUARD_ENABLED :=full
 endif
 endif
+endif
 ifeq ($(LOCAL_PROGUARD_ENABLED),disabled)
     # the package explicitly request to disable proguard.
     LOCAL_PROGUARD_ENABLED :=