Dialer: (Re-)Move more resources

* The spam notification stuff was already removed in a previous patch
  thus we don't need to explicitly keep the strings
* The "search_shortcut_" ones are defined and used in another part of
  the app
* search_shadown is unused

Change-Id: Icd22b9236830fff04737f1f7fdcec1b45a5d8c7e