Remove unused MonochromeApplication template code.

chrome/android/java/templates/monochrome_application.gni

-# 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.
-
-import("//build/config/android/config.gni")
-import("//build/config/android/rules.gni")
-
-# Generates monochrome application class.
-#
-# Variables
-#   monochrome_application_class: the name of monochrome application class.
-#   package: the package name of monochrome class.
-#   super_class: the super class of monochrome application.
-#   output: the generated application class.
-template("generate_monochrome_application") {
-  jinja_template(target_name) {
-    forward_variables_from(invoker,
-                           [
-                             "output",
-                             "monochrome_application_class",
-                             "package",
-                             "super_class",
-                           ])
-    assert(defined(output))
-    assert(defined(monochrome_application_class))
-    assert(defined(package))
-    assert(defined(super_class))
-    input = "//chrome/android/java/templates/MonochromeApplication.template"
-    variables = [
-      "package=${package}",
-      "super_class=${super_class}",
-      "monochrome_application_class=${monochrome_application_class}",
-    ]
-  }
-}