configure_dmc.yml - multiple issues in "Configure systems as search peers to be monitored except indexers" task

[igsher]

Issues with "Configure systems as search peers to be monitored except indexers" in configure_dmc.yml:

1. The task fails if 'splunk add search-server' command fails with error "A peer with uri of https://<>:8089 already exists.", instead of ignoring the error.
2. The task attempts to add the node it's running on as it's own search peer and fails. (duplicate of issue Cluster deployment fails in configure_dmc.yml #214)

Proposed fix:

- name: Configure systems as search peers to be monitored except indexers
  ansible.builtin.shell: |
    {{ splunk_home }}/bin/splunk add search-server https://{{ item }}:{{ splunkd_port }} -auth "{{ splunk_auth }}" -remoteUsername "{{ splunk_admin_username }}" -remotePassword "{{ splunk_admin_password }}"
  loop: "{{ query('inventory_hostnames', 'all:!indexer')|difference([inventory_hostname]) }}"
  become: true
  become_user: "{{ splunk_nix_user }}"
  register: dmc_add_search_peer_result
  no_log: true
  failed_when:
    - "dmc_add_search_peer_result.rc != 0"
    - "'already exists' not in dmc_add_search_peer_result.stderr"
  changed_when:
    - "'Peer added' in dmc_add_search_peer_result.stdout"