Android R Preview 4 (RPP4.200409.015)
Update clang-tools to ab/6242892 am: bc8274da91

Change-Id: I6ba66bbc8b894e71a04471769d235189e848c993
tree: 40e75dd4a241cbcf09457333343e338e73c96f2a
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml