Remove Google Play specific search URIs from Settings.

1. If there are no installed print services or NFC payment services,
   we would like to allow the user to search for one in Play. However,
   Play is Google specific and we should not have hard coded URI that
   rely on it in settings. Declare secure settings for each of these
   URI and check at runtime if the URI is non-empty, then show the
   add menu item.

bug:11011519

Change-Id: I2c5cb172015bbecd7d2f8ffd3cb7fd790b01dab8