Stop NetworkManager from overriding resolv.conf

When ``resolv_is_managed`` is set, Kayobe templates resolv.conf. This
patch stops NetworkManager from overriding these changes.

Closes-Bug: #2044537
Change-Id: I90b61dfe03d53c58327d2b15e70b7b8489bdfb47

ansible/roles/network-redhat/tasks/main.yml

@@ -4,6 +4,22 @@
   when: resolv_is_managed | bool
   become: True
 
+- name: Ensure NetworkManager DNS config is present only if required
+  become: true
+  community.general.ini_file:
+    path: /etc/NetworkManager/NetworkManager.conf
+    section: main
+    option: "{{ item.option }}"
+    value: "{{ item.value }}"
+    state: "{{ 'present' if resolv_is_managed | bool else 'absent'}}"
+  loop:
+    - option: dns
+      value: none
+    - option: rc-manager
+      value: unmanaged
+  when:
+    - ansible_facts.os_family == "RedHat" and ansible_facts.distribution_major_version == "9"
+
 - name: Configure network interfaces (RedHat)
   import_role:
     name: MichaelRigart.interfaces

releasenotes/notes/fix-resolv-conf-management-141788e64d0e82a0.yaml

+---
+fixes:
+  - |
+    Fixes a bug where NetworkManager would overwrite resolv.conf when
+    ``resolv_is_managed`` is set to ``True``.
+    `LP#2044537 <https://launchpad.net/bugs/2044537>`__