Add netdutils_test to APCT's device-tests.zip

This is required for presubmit tests to find the netdutils_test binary.

Test: as follows:
    - m device-tests
    - verify that out/.../device-tests.zip contains netdutils_test

Change-Id: I8f6de485f0fac289673ae392afc4addf51788e46
diff --git a/libnetdutils/Android.bp b/libnetdutils/Android.bp
index 78466ac..f2ad3de 100644
--- a/libnetdutils/Android.bp
+++ b/libnetdutils/Android.bp
@@ -39,6 +39,7 @@
         "SyscallsTest.cpp",
     ],
     defaults: ["netd_defaults"],
+    test_suites: ["device-tests"],
     cflags: [
         "-Wall",
         "-Werror",