[filesapp] Use token '42' for the web store in files app SWA

Bug: 1149264, 1113981
Change-Id: I5253f9eba5bd0869d32dd1757c35eb583628ad28
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2537315Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827719}

ui/file_manager/file_manager/foreground/js/ui/suggest_apps_dialog.js

@@ -196,6 +196,11 @@ class SuggestAppsDialog extends FileManagerDialogBase {
        *     token (null on error).
        */
       requestWebstoreAccessToken: function(callback) {
+        if (window.isSWA) {
+          callback('42');
+          return;
+        }
+
         chrome.fileManagerPrivate.requestWebStoreAccessToken(token => {
           if (chrome.runtime.lastError) {
             console.error(chrome.runtime.lastError.message);