use hostanem module instead of template

tasks/config.yml

@@ -1,13 +1,9 @@
 ---
 - block:
     - name: Set hostname
-      template:
+      hostname:
-        src: etc/hostname.j2
+        name: "{{ network_hostname }}"
-        dest: /etc/hostname
+      when: network_hostname
-        owner: root
-        group: root
-        mode: 0644
-      register: hostname_result
       notify: __host_reboot
 
     - name: Set hosts file
@@ -17,7 +13,6 @@
         owner: root
         group: root
         mode: 0644
-      register: hosts_result
       notify: __host_reboot
 
     - name: Add network interface configuration

templates/etc/hostname.j2

@@ -1,3 +0,0 @@
-{% if network_hostname is defined %}
-{{ network_hostname }}
-{% endif %}