Update Sunfish SVN to 20

Bug: 177091143
Change-Id: I5825f85e115818f577a2c7f96cf37442a43d3b52
(cherry picked from commit 058e4dc7680fb5f924161c436798e06116927aa3)
diff --git a/device.mk b/device.mk
index 3b66eaa..dbd2a1d 100644
--- a/device.mk
+++ b/device.mk
@@ -886,7 +886,7 @@
 
 # Increment the SVN for any official public releases
 PRODUCT_PROPERTY_OVERRIDES += \
-	ro.vendor.build.svn=18
+	ro.vendor.build.svn=20
 
 PRODUCT_COPY_FILES += \
     $(LOCAL_PATH)/powerhint.json:$(TARGET_COPY_OUT_VENDOR)/etc/powerhint.json