Build both 32 and 64 bit versions of FMQ test server

Test: Ran both 32 and 64-bit FMQ unit tests.

Bug: 33467211
Change-Id: I0d82484e3d4234e1d939458c1f7f1a80adbc7346
diff --git a/tests/Android.mk b/tests/Android.mk
index 2e61d15..ab9d450 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -31,6 +31,11 @@
     libfmq
 LOCAL_CFLAGS := -Wall -Werror
 LOCAL_SHARED_LIBRARIES += android.hardware.tests.msgq@1.0
+
+LOCAL_MULTILIB := both
+LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
+LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
+
 include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)