Fix HDPI images

* Commit 8b0f4a442 "Old-school Holo UX" changed
  these to something out of sync with the rest,
  and also broke recovery on the devices that fell into
  this density bucket.
* Restore the AOSP images.

Change-Id: If55a9925903d9bb1cfc77d6752666c7e2e6d20fe