Merge tag android-5.1.0_r1 into AOSP_5.1_MERGE

Change-Id: I5e837807d013584b2fd815aabf8f97864c5aaf12
tree: c894743ec79f1bc5359ab64dc05a71b9a5865187
  1. doc/
  2. include/
  3. src/
  4. tests/
  5. tools/