Use a separate personal/work tabs layout for the widget picker

1. Apps are feminine while widgets are masculine in some languages.
   We should use a different set of strings to ensure strings are
   translated with the right context.
2. We will be using a different theme for widget tabs. Let's keep
   the layout separate.

Bug: 184613311
Test: manual
Change-Id: I88df8ca6091e4b6ddf81f34f180a6ce2cada16e3