Merge cherrypicks of [3546446, 3547427, 3547428, 3547429, 3547413, 3547414, 3547415, 3547447, 3547430, 3546694] into pi-release

Change-Id: I46cd7ece12c5f2892711a170074e2e0bc1491e00
tree: 946f97a6baba7b620d378adce13e8a628deea96a
  1. prebuilt/
  2. Android.mk
  3. CleanSpec.mk
  4. README