virtualenv-tools has a bug which gets triggered in gates: it can't change the shebang of a virtualenv python bin/ files if they were generated with a virtualenv script whose shebang ends with python2 instead of python. Because we can't modify virtualenv-tools, we use shell scripts instead. Change-Id: Icbe6b72cebede21de7a63f3a5340ee11a50e6fd3 Partial-Bug: #1741634