Revert \"Update build-tools to ab/3050982\"
am: b3824a4dac

Change-Id: I918c818ff6841f2862b17cd7b1918be2fa82d0ab
tree: 3e569a3a50211ac34c1041c7cb573fb662003fd8
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh