Update SVN for Walleye/Taimen to 21 for December release
bug: 117667960
(cherry picked from commit c3df45169762eafdcc93ced580e5b9cd54ba2f6b)

Change-Id: Ibf3e69bd4ed3b252d237ede91a4a1f2149fee899
diff --git a/device.mk b/device.mk
index 9ea2203..2b4a428 100755
--- a/device.mk
+++ b/device.mk
@@ -36,7 +36,7 @@
 
 # Set the SVN for the targeted MR release
 PRODUCT_PROPERTY_OVERRIDES += \
-    ro.vendor.build.svn=20
+    ro.vendor.build.svn=21
 
 # Enforce privapp-permissions whitelist
 PRODUCT_PROPERTY_OVERRIDES += \