Enable host multilib for ART testing.

Change-Id: I7827331202482e28e824fc6583f590ddadaa2087
diff --git a/NativeCode.mk b/NativeCode.mk
index 98e87b0..12e8114 100644
--- a/NativeCode.mk
+++ b/NativeCode.mk
@@ -127,6 +127,7 @@
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/NativeCode.mk
 LOCAL_SHARED_LIBRARIES += $(core_shared_libraries) libexpat-host libicuuc-host libicui18n-host libcrypto-host libz-host
 LOCAL_STATIC_LIBRARIES += $(core_static_libraries) libziparchive-host libutils
+LOCAL_MULTILIB := both
 include $(BUILD_HOST_SHARED_LIBRARY)
 
 ifeq ($(LIBCORE_SKIP_TESTS),)