DO NOT MERGE - Merge pi-dev@5234907 into stage-aosp-master

Bug: 120848293
Change-Id: Ifde0e7dd0896f48be8975b153a07953bcea72656
tree: e92a8b419a0ff3796e55e99f212516a9b1696cbb
  1. Android.mk
  2. CleanSpec.mk
  3. README
  4. prebuilt/