Eleven: Only enable proguard obfuscation on user builds

Change-Id: Ib0c0ad1ada0bd29fff594baaf6b4a77740485416
diff --git a/Android.mk b/Android.mk
index 0d41b4d..3f7501b 100644
--- a/Android.mk
+++ b/Android.mk
@@ -15,8 +15,12 @@
 LOCAL_PACKAGE_NAME := Eleven
 LOCAL_OVERRIDES_PACKAGES := Music
 
-LOCAL_PROGUARD_ENABLED := obfuscation
 LOCAL_PROGUARD_FLAGS := -include $(LOCAL_PATH)/proguard.cfg
+ifeq ($(TARGET_BUILD_VARIANT),user)
+    LOCAL_PROGUARD_ENABLED := obfuscation
+else
+    LOCAL_PROGUARD_ENABLED := disabled
+endif
 
 include $(BUILD_PACKAGE)