
`update_engine_version.{ps1|sh}` needs to operate on a foreign repository. When flutter is run in a git-hook, these environment variables will override our git calls location and corrupt the install. fixes: #165390
`update_engine_version.{ps1|sh}` needs to operate on a foreign repository. When flutter is run in a git-hook, these environment variables will override our git calls location and corrupt the install. fixes: #165390