message: Don't use refreshenv
diff: if defined KOKORO_BUILD_ID (
  echo Installing CMake
  choco install cmake -y
  - refreshenv
  + call RefreshEnv.cmd
  echo Installing LLVM
  choco install llvm --version 8.0.0 -y
  - refreshenv
  + call RefreshEnv.cmd
  )
  -if errorlevel 1 exit /b %errorlevel%
  :: Put Visual Studio tools on the PATH
  call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" amd64
  