Update Wahoo SVN to 31

Bug:126590667
Change-Id: I048357eb4b33d84c4fac303c0f5dd44aae7614cb
(cherry picked from commit d46799a735c1f3086a3d3e07bcc70b9a00c58b09)
diff --git a/device.mk b/device.mk
index 780eb48..837010d 100755
--- a/device.mk
+++ b/device.mk
@@ -47,7 +47,7 @@
 
 # Set the SVN for the targeted MR release
 PRODUCT_PROPERTY_OVERRIDES += \
-    ro.vendor.build.svn=30
+    ro.vendor.build.svn=31
 
 # Enforce privapp-permissions whitelist
 PRODUCT_PROPERTY_OVERRIDES += \