twinapi.appcore: Return success from AdvertisingManager_get_AdvertisingId stub.

dlls/twinapi.appcore/advertising_manager.c

@@ -117,7 +117,7 @@ DEFINE_IINSPECTABLE( statics, IAdvertisingManagerStatics, struct factory, IActiv
 static HRESULT WINAPI statics_get_AdvertisingId( IAdvertisingManagerStatics *iface, HSTRING *out )
 {
     FIXME( "iface %p, out %p stub!\n", iface, out );
-    return E_NOTIMPL;
+    return WindowsCreateString( NULL, 0, out );
 }
 
 static const struct IAdvertisingManagerStaticsVtbl statics_vtbl =

dlls/twinapi.appcore/tests/twinapi.c

@@ -220,6 +220,10 @@ static void test_AdvertisingManager(void)
     hr = IActivationFactory_QueryInterface( factory, &IID_IAdvertisingManagerStatics, (void **)&advertising_manager_statics );
     ok( hr == S_OK, "got hr %#lx.\n", hr );
 
+    hr = IAdvertisingManagerStatics_get_AdvertisingId( advertising_manager_statics, &str );
+    ok( hr == S_OK, "got hr %#lx.\n", hr );
+    WindowsDeleteString( str );
+
     ref = IAdvertisingManagerStatics_Release( advertising_manager_statics );
     ok( ref == 2, "got ref %ld.\n", ref );
     ref = IActivationFactory_Release( factory );