-Check if network-manager is installed before modifying netplan

-fix .xscreensaver owner and group

roles/lubuntu/tasks/main.yaml

@@ -1,4 +1,6 @@
 ---
+- name: Include OS-specific variables
+  include_vars: "check_packages.yaml"
 
 - name: install required packages
   become: true
@@ -29,6 +31,14 @@
     group: "{{ def_username }}"
   tags: powermanagement
 
+- name: "Check if listed package is installed"
+  package:
+    name: "{{ item }}"
+    state: present
+  check_mode: true
+  loop: "{{ package_names }}"
+  register: network_manager
+
 - name: change netplan network renderer
   become: true
   ansible.builtin.lineinfile:
@@ -36,11 +46,12 @@
     state: present
     line: "  renderer: NetworkManager"
     insertafter: "  version: 2"
+  when: network_manager is succeeded
 
 - name: disable screensaver 3
   ansible.builtin.copy:
     dest: "/home/{{ def_username }}/.xscreensaver"
     src: "{{ role_path }}/files/_xscreensaver"
-    owner: eve
-    group: eve
+    owner: "{{ def_username }}"
+    group: "{{ def_username }}"
 

roles/lubuntu/vars/check_packages.yaml

@@ -0,0 +1,3 @@
+---
+package_names:
+  - network-manager