turn off NetworkManager in CentOS-8 TripleO

NetworkManager is restarting unexpectedly during
deployments of TripleO. Ensure the service is
disabled prior to deployment

Partial-Bug: #1885286
Change-Id: I67501aaaf34c8fdfa09da37e0e0a3eb6982cff3a

playbooks/tripleo-ci/pre.yaml

@@ -3,3 +3,4 @@
   roles:
     - role: common
     - role: prepare-node
+    - role: disable_network_manager

roles/disable_network_manager/tasks/main.yml

@@ -0,0 +1,25 @@
+- name: disable NetworkManager
+  block:
+    - name: dump network manager info
+      command: nmcli
+      register: nmcli_info
+
+    - name: print network manager info
+      debug:
+        msg: "{{ nmcli_info.stdout_lines }}"
+
+    - name: stop NetworkManager
+      become: true
+      systemd:
+        state: stopped
+        enabled: no
+        name: NetworkManager
+
+    - name: dump ip info
+      command: ip a
+      register: ip_info
+
+    - name: print ip info
+      debug:
+        msg: "{{ ip_info.stdout_lines }}"
+  when: ansible_distribution_major_version|int >= 8