Allow to tag owner to PRODUCT_COPY_FILES

PRODUCT_COPY_FILES now is a list of words like <source
path>:<destination path>[:<owner>].
The optional :<owner> is used to indicate the owner of a vendor file.

Bug: 7048854
Change-Id: I435d1e18b7a091fb62513062cfc2e420e51557ec
diff --git a/core/product.mk b/core/product.mk
index 20d1e97..c0e6e3e 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -165,7 +165,7 @@
     $(eval pb := $(strip $(PRODUCTS.$(p).PRODUCT_BRAND))) \
     $(if $(pb),,$(error $(p): PRODUCT_BRAND must be defined.)) \
     $(foreach cf,$(strip $(PRODUCTS.$(p).PRODUCT_COPY_FILES)), \
-      $(if $(filter 2,$(words $(subst :,$(space),$(cf)))),, \
+      $(if $(filter 2 3,$(words $(subst :,$(space),$(cf)))),, \
         $(error $(p): malformed COPY_FILE "$(cf)") \
        ) \
      ) \