omni: move to PRODUCT_SYSTEM_DEFAULT_PROPERTIES

Change-Id: I76c0a4a3b6c4572f1b0197c4fc39151640ef9de1
diff --git a/config/phone-xxxhdpi-3072-dalvik-heap.mk b/config/phone-xxxhdpi-3072-dalvik-heap.mk
index 7127ff4..3d4ed79 100644
--- a/config/phone-xxxhdpi-3072-dalvik-heap.mk
+++ b/config/phone-xxxhdpi-3072-dalvik-heap.mk
@@ -16,7 +16,7 @@
 
 # Provides overrides to configure the Dalvik heap for a 3G phone
 
-PRODUCT_PROPERTY_OVERRIDES += \
+PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
     dalvik.vm.heapstartsize=16m \
     dalvik.vm.heapgrowthlimit=256m \
     dalvik.vm.heapsize=512m \