Stop setting use_qualified_include to true now that that is the default.

ash/strings/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("//tools/grit/grit_rule.gni")
 import("//tools/grit/repack.gni")
 
 assert(is_chromeos)
 
 grit("strings") {
   source = "../ash_strings.grd"
-  use_qualified_include = true
   outputs = [
     "grit/ash_strings.h",
     "ash_strings_am.pak",
     "ash_strings_ar.pak",
     "ash_strings_bg.pak",
     "ash_strings_bn.pak",
     "ash_strings_ca.pak",
     "ash_strings_cs.pak",
     "ash_strings_da.pak",
     "ash_strings_de.pak",
@@ skipping 69 matching lines @@
       "//ui/strings:ui_strings",
     ]
   }
 }
 
 # Creates a pak file containing en-US strings for ash_unittests, etc.
 repack_one_locale_ash("ash_test_strings") {
   output = "$root_build_dir/ash_test_strings.pak"
   locale = "en-US"
 }