Fix chrome://webapks page

The page does not load because failing the trusted type policy.
Removing import "strings.m.js" since we are not using it.

Bug: 1141097
Change-Id: Ief36638834ac481f1da6ce98c94c6c60308f54c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2492890Reviewed-by: Glenn Hartmann <hartmanng@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Ella Ge <eirage@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820318}

chrome/browser/resources/webapks/about_webapks.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import './strings.m.js';
-
 import {addWebUIListener} from 'chrome://resources/js/cr.m.js';
 import {$, createElementWithClassName} from 'chrome://resources/js/util.m.js';