Add support for verity builds to the build system.

Change-Id: I3ef908d8d52ec88de453b161bbc3f198517a72f1
diff --git a/core/product.mk b/core/product.mk
index a2f4abc..b3fb6e7 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -97,7 +97,10 @@
     PRODUCT_FACTORY_RAMDISK_MODULES \
     PRODUCT_FACTORY_BUNDLE_MODULES \
     PRODUCT_RUNTIMES \
-    PRODUCT_BOOT_JARS
+    PRODUCT_BOOT_JARS \
+    PRODUCT_SUPPORTS_VERITY \
+    PRODUCT_VERITY_PARTITION \
+    PRODUCT_VERITY_SIGNING_KEY
 
 
 define dump-product