Restructure public side of network service.

mojo/services/network/public/interfaces/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 
-mojom("network") {
+mojom("interfaces") {
   sources = [
     "cookie_store.mojom",
     "net_address.mojom",
     "network_error.mojom",
     "network_service.mojom",
     "tcp_bound_socket.mojom",
     "tcp_connected_socket.mojom",
     "tcp_server_socket.mojom",
     "udp_socket.mojom",
     "url_loader.mojom",
     "web_socket.mojom",
   ]
 }