Bump bonito SVN to 15

bug:141626492
(cherry picked from commit b43955658053e816b16f5efe84f383f9b8fc813d)

Change-Id: I4fe45a687b0cde08ac979dc8292eaacb5afa3904
diff --git a/device.mk b/device.mk
index baa15ea..161e223 100644
--- a/device.mk
+++ b/device.mk
@@ -877,4 +877,4 @@
 
 # Increment the SVN for any official public releases
 PRODUCT_PROPERTY_OVERRIDES += \
-	ro.vendor.build.svn=13
+	ro.vendor.build.svn=15