Update git submodules

* Update prebuilts/build-tools from branch 'master'
  to d020de865fb0d220e9928ccb46c500888634b9ea
  - Merge "Update build-tools to ab/6702419"
  - Update build-tools to ab/6702419
    
    https://ci.android.com/builds/branches/aosp-build-tools-release/grid?head=6702419&tail=6702419
    
    Test: treehugger
    Change-Id: I60857ed3b02cba784a038a8b2384f9049522af79
    
1 file changed