Add merge-abi-diff to merge abi diff reports. am: ce1c0735e1
am: ed803ee919

Change-Id: Iee5be7811532e7105272ff6c9b84b4183907d3a4
tree: 9145308746f31a5cbcc9e8b13e8a681647dd0460
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml