[Service Manager] Get rid of dynamic service discovery

services/service_manager/public/constants.gni

Index: services/service_manager/public/constants.gni
diff --git a/services/service_manager/public/constants.gni b/services/service_manager/public/constants.gni
deleted file mode 100644
index 19364268367bc59f23872e67d6c2967b286b3b0a..0000000000000000000000000000000000000000
--- a/services/service_manager/public/constants.gni
+++ /dev/null
@@ -1,8 +0,0 @@
-# Copyright 2016 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.
-
-declare_args() {
-  # Service package directories are created within this subdirectory.
-  packages_directory = "Packages"
-}