when debugging features are enabled (i.e. sshd is automatically started with well known ssh keys and passwords), we should include a big fat warning on the login screen telling people to not log in with any account they care about.  since the system is listening on the network with (effectively) completely wide open ssh access, anything they do on the device can be stolen.

debugd exposes QueryDevFeatures over dbus which Chrome already uses.  the warning should be displayed if DEV_FEATURE_SSH_SERVER_CONFIGURED is set.