Use SIM-only contacts with Nexus 4
You could try to install SIM Contacts. I've not seen how to make it your default app for managing contacts, but I suppose you could drag the app icon to your homescreen or to the dock, so you can just access it quickly from there.

With the SIM Contacts app, you can add, edit (long-press on a contact and a menu will appear), or delete SIM contacts. You can also choose to copy them on your phone.

UPDATE #1: From Izzy: 


  Also, if you don't want anything to be synced to Google, make sure to
  turn off all sync options in Settings → Accounts &amp; Sync. By default, that's all enabled. 


As long as you add new contacts as SIM contacts, they will not be synched to Google. Only contacts added as Google contacts will be synched.