Multiple errors on wrong password entry at lock screen

[gngram]

Description of changes

Multiple error appears when wrong password is entered to unlock the Ghaf laptop.
gtklock tries to authenticate multiple times (as in gtklock PAM configuration) with PAM using same password even if it is wrong. This patch fixes the issue in PAM converse method and stops repeated authentications when it fails.
It also uses lock layout from gtklock package and removes layout defined in Ghaf which seems to be similar.

A PR in gtklock is underway, we'll remove this fix once it is available in upstream project:

jovanlanik/gtklock#119

Checklist for things done

• Summary of the proposed changes in the PR description
• More detailed description in the commit message(s)
• Commits are squashed into relevant entities - avoid a lot of minimal dev time commits in the PR
• Contribution guidelines followed
• Ghaf documentation updated with the commit - https://tiiuae.github.io/ghaf/
• PR linked to architecture documentation and requirement(s) (ticket id)
• Test procedure described (or includes tests). Select one or more:
  • Tested on Lenovo X1 x86_64
  • Tested on Jetson Orin NX or AGX aarch64
  • Tested on Polarfire riscv64
• Author has run make-checks and it passes
• All automatic Github Action checks pass - see actions
• Author has added reviewers and removed PR draft status
• Change requires full re-installation
• Change can be updated with nixos-rebuild ... switch

Instructions for Testing

• List all targets that this applies to:

  • All Ghaf platforms, which use gtklock

• Is this a new feature

  • List the test steps to verify:
    • Boot the Ghaf machine and login using proper credentials.
    • Lock the machine.
    • Try to unlock it using wrong password
      • Without this fix, you will see multiple authentication errors
      • With this fix it will show "login failed"
    • Please make sure every controls on lock screen functions properly.

• If it is an improvement how does it impact existing functionality?

[brianmcgillion]

Can you link the PR to the upstream project into the commit message for tracking purposes. Then it will be easy to know when to remove this overlay when merged upstream.