openpilot UI replay experience on fresh install

[stefpi]

On a fresh install, if you run tools/replay/replay --demo and then ./selfdrive/ui/ui.py in a different terminal, you will be stuck on this screen (after going through accepting terms).

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To get past this, you can run a replay with --dcam, wait for openpilot to detect the drivers face and then press the checkmark when it becomes enabled.

Would be good to have a way to disable these checks if the user is running the UI on a PC for development only.

[TheSecurityDev]

You can also run BIG=1 ./selfdrive/ui/ui.py and you can go through that training successfully