DO NOT MERGE - Merge Pie Bonito/Sargo into master.

Bug: 131756210
Change-Id: I004b1a9f8cc7dd1b12d4b0c7d58255a5f48810d3
tree: e92a8b419a0ff3796e55e99f212516a9b1696cbb
  1. Android.mk
  2. CleanSpec.mk
  3. README
  4. prebuilt/