main/postmarketos-ui-phosh: switch greeter to lightdm-mobile-greeter
This adds the lightdm-mobile-greeter to the phosh UI package, it visually looks quite similar to the lockscreen in phosh (since it uses handy)
The main feature is this removes the need to have the username in a config file, so a new user created using adduser will just work.
Edited by Bart Ribbers