Pass OUT_DIR variable to atree.

Change-Id: Iabbe905341dfe970448682a9dcbb170a04ad5222
diff --git a/core/Makefile b/core/Makefile
index 29c4043..e67f9dd 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1368,6 +1368,7 @@
 			-I $(HOST_OUT) \
 			-I $(TARGET_COMMON_OUT_ROOT) \
 			-v "PLATFORM_NAME=android-$(PLATFORM_VERSION)" \
+			-v "OUT_DIR=$(OUT_DIR)" \
 			-o $(PRIVATE_DIR) && \
 		cp -f $(target_notice_file_txt) \
 				$(PRIVATE_DIR)/platforms/android-$(PLATFORM_VERSION)/images/NOTICE.txt && \