Update Sunfish SVN to 15

Bug: 168709737
Change-Id: Ia0679bc0f4c6668a01d3dc1485d062ce7bcff360
(cherry picked from commit 60869c86b8c1eafed70ce9ff69fc35b6c7d63a9f)
diff --git a/device.mk b/device.mk
index bcdb0cf..9ee0bd6 100644
--- a/device.mk
+++ b/device.mk
@@ -878,7 +878,7 @@
 
 # Increment the SVN for any official public releases
 PRODUCT_PROPERTY_OVERRIDES += \
-	ro.vendor.build.svn=14
+	ro.vendor.build.svn=15
 
 # ZRAM writeback
 PRODUCT_PROPERTY_OVERRIDES += \