Move the test template to //testing/test.gni (part 2)

third_party/libaddressinput/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("//testing/rules.gni")
 import("//tools/grit/grit_rule.gni")
 
 libaddressinput_util_files = [
   "src/cpp/src/address_data.cc",
   "src/cpp/src/address_field.cc",
   "src/cpp/src/address_field_util.cc",
   "src/cpp/src/address_formatter.cc",
   "src/cpp/src/address_metadata.cc",
   "src/cpp/src/address_ui.cc",
   "src/cpp/src/format_element.cc",
@@ skipping 241 matching lines @@
     deps = [
       ":libaddressinput",
       ":strings",
       "//base:prefs",
       "//base/test:run_all_unittests",
       "//net:test_support",
       "//testing/gtest",
     ]
   }
 }