Subsequent shells e.g. `kubectl/docker exec` don't enter as the expected user

[djmcgreal-cc]

I.e. using https://github.com/coder/envbuilder-starter-devcontainer, which sets up user coder when docker exec get:

root@remote-development:/workspaces/envbuilder-starter-devcontainer#

Can then sudo -su coder and the environment is as expected.