Allow maridbcheck socket to FreeBind

Once we've removed network.target from wanted targets for
mariadbcheck.socket, it started to fail to startup intermitently in LXC
deployments, since it was trying to bind on IP address that is not
brought up yet. At the same time we can't wait for IP being up, as
OVS while providing network, waits for socket.target as it needs
to have ovsdb started up, so waiting for network.target does
create circular dependency.

To avoid that we're allowing socket to bind on IP even when IP is not
UP yet. Other possible solution would be to bind on 0.0.0.0.

Depends-On: https://review.opendev.org/c/openstack/openstack-ansible/+/872896
Change-Id: Ia4cde2153813e68419d261cd94e3017523177142
Closes-Bug: #2003631
Related-Bug: #2002653
(cherry picked from commit 8a8d29ea49)

tasks/galera_server_post_install.yml

@@ -50,6 +50,7 @@
         enabled: False
         load: False
         standard_output: "socket"
+        after_targets: []
         sockets:
           - socket_name: "mariadbcheck"
             enabled: "{{ galera_monitoring_check_enabled }}"
@@ -59,6 +60,7 @@
               IPAddressDeny: any
               IPAddressAllow: "{{ (galera_monitoring_allowed_source is defined) | ternary(galera_monitoring_allowed_source, 'localhost') }}"
               Accept: "yes"
+              FreeBind: "true"
   tags:
     - galera-service