Build multilib host libexpat.

Bug: 13751317
Change-Id: I7e6a7740dbf0a26ed0faca5cb108386616ea1442
diff --git a/Android.mk b/Android.mk
index 4b13262..8e3eaf0 100644
--- a/Android.mk
+++ b/Android.mk
@@ -40,6 +40,8 @@
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_MODULE_TAGS := optional
 
+LOCAL_MULTILIB := both
+
 include $(BUILD_HOST_STATIC_LIBRARY)