modifying extra packages to include vars files from playbook level

roles/extra_packages/tasks/main.yml

 ---
-- name: load vars
+- name: load extra_packages from play
+  include_vars: "vars/extra_packages_{{ ansible_distribution }}_{{ ansible_distribution_major_version }}.yml"
+  when: extra_packages is not defined
+
+- name: load vars from role
   include_vars: "{{ ansible_distribution }}_{{ ansible_distribution_major_version }}.yml"
   when: extra_packages is not defined