Allow proto builds to pass in java proto params.

Change-Id: I65fe0cd96f818f59267da6159e6bd2ad28f07a11
diff --git a/core/base_rules.mk b/core/base_rules.mk
index f0a6398..f6497da 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -264,6 +264,7 @@
   endif
 endif
 $(proto_java_sources_file_stamp): PRIVATE_PROTOC_FLAGS := $(LOCAL_PROTOC_FLAGS)
+$(proto_java_sources_file_stamp): PRIVATE_PROTO_JAVA_OUTPUT_PARAMS := $(LOCAL_PROTO_JAVA_OUTPUT_PARAMS)
 $(proto_java_sources_file_stamp) : $(proto_sources_fullpath) $(PROTOC)
 	$(call transform-proto-to-java)