Reissue notification about each Plugin VM start failure

We need to re-notify the user about each and every failure to start
Plugin VM, otherwise, if notification was closed, but not dismissed, the
failure appears to be silent.

Bug: b/155685388
Change-Id: I018af01601562747053b0ade7b0c3e214728c1b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2211156Reviewed-by: Timothy Loh <timloh@chromium.org>
Commit-Queue: Dmitry Torokhov <dtor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#770934}

chrome/browser/chromeos/plugin_vm/plugin_vm_manager_impl.cc

@@ -87,6 +87,7 @@ void ShowStartVmFailedNotification(Profile* profile,
           {}, new message_center::NotificationDelegate(),
           kNotificationPluginVmIcon,
           message_center::SystemNotificationWarningLevel::WARNING);
+  notification->set_renotify(true);
   NotificationDisplayServiceFactory::GetForProfile(profile)->Display(
       NotificationHandler::Type::TRANSIENT, *notification,
       /*metadata=*/nullptr);