main/postmarketos-ui-phosh: re-enable autologin
We have tried out lightdm-mobile-greeter for three weeks, but let's remove it again from the default install. The greeter behaves completely different from the Phosh (or any other UI's) lockscreen, therefore it provides a bad user experience. Not only the design is different, but it also can't display the same information as the Phosh lockscreen. You can't accept a call coming in while the greeter is displayed, and whatever other features will be added to the lockscreen in the future would not be in the greeter (e.g. making a photo without logging in, emergency calls without login, ...). It's clear to me now, that postmarketOS in the default installation should install one UI in single-user mode, and that UI should use its lockscreen to display all login screens. The case of having multiple UIs installed at the same time is used rarely, so instead of optimizing for it, document how to enable a greeter after the installation in the wiki: https://wiki.postmarketos.org/wiki/Configure_postmarketOS_for_multiple_UIs_or_users Besides the strong reasons above to ship with no greeter at all, we had problems with lightdm-mobile-greeter in particular: * It did not work with Plasma Mobile * When HDMI was plugged in, the greeter was not usable (especially annoying, because Phosh tends to crash after plugging in HDMI, so it would go back to the greeter which then means you need to reboot) This reverts commit be693339.
I've verified with qemu that this boots into phosh with autologin again.
Leading up to this MR, I did a lot of soul searching related to display managers in postmarketOS (how can we get rid of setting the username in post-install? how do we display phosh lockscreen on boot?) and I think I found a good path forward in #823 (closed) (let's discuss that there).