Update build-tools to ab/3916447 am: eb2e878dfa am: f71bfb82ac
am: eb4eb3ff48

Change-Id: Ia92b066c3a2ef8b91b046a0f0bc8483e6402ea00
tree: fa7607f1a6931d8c2b67cc23edb59fa05373a83d
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml