Build CTS tests as multilib apks

CTS-tradefed uses the same apk for both 32 and 64 bit tests.

Bug: 17924614
Change-Id: Idbf2d93c54efbb1c281ad9e93f0f39430614df61
diff --git a/tests/cts/net/Android.mk b/tests/cts/net/Android.mk
index da19a4d..46d4d81 100644
--- a/tests/cts/net/Android.mk
+++ b/tests/cts/net/Android.mk
@@ -21,6 +21,9 @@
 # and when built explicitly put it in the data partition
 LOCAL_MODULE_PATH := $(TARGET_OUT_DATA_APPS)
 
+# Include both the 32 and 64 bit versions
+LOCAL_MULTILIB := both
+
 LOCAL_JAVA_LIBRARIES := voip-common conscrypt
 
 LOCAL_JNI_SHARED_LIBRARIES := libnativedns_jni