Ensure registry is shutdown

src/core/surface/init.c

@@ -92,6 +92,7 @@ void grpc_shutdown(void) {
     census_shutdown();
     grpc_timers_global_destroy();
     grpc_tracer_shutdown();
+    grpc_resolver_registry_shutdown();
   }
   gpr_mu_unlock(&g_init_mu);
 }