* Update install_log2ram.yml

Updated Ansible playbook to configure notification settings in Log2Ram...

The playbook incorrectly referenced 'MAIL=' - this should instead be 'NOTIFICATION='

Added support for customizable notification commands - 'NOTIFICATION_COMMAND='

* Update install_log2ram.yml

Aligned Ansible playbook settings with Log2Ram config defaults to ensure consistency and predictability.

* Update install_log2ram.yml

Added a task to install the prerequisite apt package 'gnupg'.

(GnuPG is required by the task, 'Add gpg key').