Make chrome://site-engagement non-polymer and re-enable on Android.

chrome/browser/resources/engagement/engagement_table.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. */
-
-table,
-table td,
-table th {
-  border: 1px solid #777;
-  border-collapse: collapse;
-  padding-left: 4px;
-  padding-right: 4px;
-}
-
-table th {
-  background: rgb(224, 236, 255);
-  cursor: pointer;
-  padding-bottom: 4px;
-  padding-top: 4px;
-  white-space: nowrap;
-}
-
-.origin-cell {
-  min-width: 500px;
-}
-
-table tr:hover {
-  background: rgb(255, 255, 187);
-}
-
-.sort-column::after {
-  content: '▲';
-}
-
-:host([sort-reverse]) .sort-column::after {
-  content: '▼';
-}
-
-paper-slider {
-  width: 300px;
-  --paper-slider-input: {
-    width: 70px;
-  };
-}