libbinder_ndk: test vendor/system stability

A vendor stability binder shouldn't be able to call into a system
stability binder. Before, we were missing a negative test.

Bug: 136027762
Test: binderVendorDoubleLoadTest
Change-Id: I4944c5c61d42873798dac9c132b743469a80dd63
diff --git a/libs/binder/ndk/test/Android.bp b/libs/binder/ndk/test/Android.bp
index 1c5dba3..ebd08b2 100644
--- a/libs/binder/ndk/test/Android.bp
+++ b/libs/binder/ndk/test/Android.bp
@@ -77,6 +77,7 @@
     static_libs: [
         "IBinderVendorDoubleLoadTest-cpp",
         "IBinderVendorDoubleLoadTest-ndk_platform",
+        "libbinder_aidl_test_stub-ndk_platform",
     ],
     shared_libs: [
         "libbase",