ART: Fix libnativebridgetest dependencies

Fix typo.

Test: m test-art-host
Change-Id: I1a272a8aa2a114c108cc306164df78f568be20d7
diff --git a/test/Android.libnativebridgetest.mk b/test/Android.libnativebridgetest.mk
index 5c97e4d..aa83016 100644
--- a/test/Android.libnativebridgetest.mk
+++ b/test/Android.libnativebridgetest.mk
@@ -61,7 +61,7 @@
     LOCAL_CLANG := $(ART_HOST_CLANG)
     LOCAL_CFLAGS := $(ART_HOST_CFLAGS) $(ART_HOST_DEBUG_CFLAGS)
     LOCAL_ASFLAGS := $(ART_HOST_ASFLAGS) $(ART_HOST_DEBUG_ASFLAGS)
-    LOCAL_SHARED_LIBRARIES := libcutils
+    LOCAL_SHARED_LIBRARIES += libcutils
     LOCAL_LDLIBS := -ldl -lpthread
     ifeq ($(HOST_OS),linux)
       LOCAL_LDLIBS += -lrt