Fix proguard flag file dependency.

Change-Id: Ic9f90a30833bfafb7d76dcc851a92892b9a2a9b7
diff --git a/Android.mk b/Android.mk
index dc72ec6..5285e18 100644
--- a/Android.mk
+++ b/Android.mk
@@ -28,6 +28,6 @@
 
 LOCAL_OVERRIDES_PACKAGES := Home
 
-LOCAL_PROGUARD_FLAGS := -include $(LOCAL_PATH)/proguard.flags
+LOCAL_PROGUARD_FLAG_FILES := proguard.flags
 
 include $(BUILD_PACKAGE)