Define and set initial svn=1

Bug: 126762998
Change-Id: I09023005c90a8fcb086c1c239d6f1049ad63548a
diff --git a/device.mk b/device.mk
index e5bcdd6..ad45cf3 100644
--- a/device.mk
+++ b/device.mk
@@ -802,3 +802,7 @@
 # GTS ACSA(Agreement for Carrier Service Application) verification
 PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
     ro.com.google.acsa=true
+
+# Increment the SVN for any official public releases
+PRODUCT_PROPERTY_OVERRIDES += \
+	ro.vendor.build.svn=1