nixos/modules/config/nsswitch.nix uses `passwdArray` for both `passwd`
and `group`, but when moving this into the google-oslogin module in
4b71b6f8fa, it didn't get split
appropriately.
The OS Login package enables the following components:
AuthorizedKeysCommand to query valid SSH keys from the user's OS Login
profile during ssh authentication phase.
NSS Module to provide user and group information
PAM Module for the sshd service, providing authorization and
authentication support, allowing the system to use data stored in
Google Cloud IAM permissions to control both, the ability to log into
an instance, and to perform operations as root (sudo).
