[MD settings] update settings title bar

chrome/browser/resources/settings/settings_ui/settings_ui.css

-/* Copyright 2015 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. */
-
-:host {
-  @apply(--layout-vertical);
-  @apply(--layout-fit);
-  -webkit-user-select: none;
-  background-color: var(--paper-blue-grey-50);
-}
-
-paper-toolbar {
-  @apply(--shadow-elevation-4dp);
-  background-color: rgb(52, 73, 94);
-  height: 56px;
-  position: relative;
-  z-index: 10;
-}
-
-paper-drawer-panel {
-  @apply(--layout-center);
-  --paper-drawer-panel-left-drawer-container: {
-    background-color: rgb(236, 239, 241);
-    margin-top: 8px;
-  };
-  position: relative;
-}
-
-settings-main paper-icon-button {
-  z-index: 10;
-}