Lock Screen and Login Screen should use same onscreen keyboard

[FlameSoulis]

Right now, you can configure the keyboard for the login screen for touch screen devices and accessibility. However, this is not the case for the lock screen. Considering secure passwords will contain numbers, the provided lock screen keyboard is limited and cannot be changed, unlike the case of the login screen.

This could potentially also be related to #802, as this would also result in the onscreen keyboards being identical. This could also address #651 as well.