Add factory to create AOSP overlays

* And return a null Logger in the AOSP contacts code
  so we don't expose the name "clearcut".
* We also don't need a no-op Logger impl anymore.

Bug 26985491

Change-Id: I18b1fe76f09012acd067d0c186f25f6eb7530bb3
(cherry picked from commit 99a05151699230f7c93311ceab50e7902c8596be)