Update build-tools to ab/4524985 am: 7ec2be6859 am: 9dcd3c19ec
am: 3a3b422632

Change-Id: I4c446ca32bc17668fb20da7b47fc89079a93d739
tree: 271daec82d4b433202a15012c003273a33dc7d1e
  1. common/
  2. darwin-x86/
  3. linux-x86/
  4. build-prebuilts.sh
  5. manifest.xml
  6. OWNERS