ToT enable #enable-app-shortcuts-search

This happens when user installed 10+ android apps. It is because icon related calls are not trivial time (2ms). So the original solution passing all shortcuts to Chrome is not optimal!

Propose this new mojo API between Chrome and android:
  GetAppShortcutGlobalQueryItems(
      string query, int32 max_results) =>
          (array<AppShortcutItem> shortcut_items);