Add streaming proto option to the build system.

Test: make w/ other prereq changes
Change-Id: Ie8711878e244074a9a3c128467eeb4908c2ef008
diff --git a/core/java_common.mk b/core/java_common.mk
index 1119a37..aea6eb3 100644
--- a/core/java_common.mk
+++ b/core/java_common.mk
@@ -54,7 +54,12 @@
   ifeq ($(LOCAL_PROTOC_OPTIMIZE_TYPE),nano)
 $(proto_java_sources_file_stamp): PRIVATE_PROTO_JAVA_OUTPUT_OPTION := --javanano_out
   else
+    ifeq ($(LOCAL_PROTOC_OPTIMIZE_TYPE),stream)
+$(proto_java_sources_file_stamp): PRIVATE_PROTO_JAVA_OUTPUT_OPTION := --javastream_out
+$(proto_java_sources_file_stamp): $(HOST_OUT_EXECUTABLES)/protoc-gen-javastream
+    else
 $(proto_java_sources_file_stamp): PRIVATE_PROTO_JAVA_OUTPUT_OPTION := --java_out
+    endif
   endif
 endif
 $(proto_java_sources_file_stamp): PRIVATE_PROTOC_FLAGS := $(LOCAL_PROTOC_FLAGS)