Load ip_vs module from the host

Currently the ip_vs module is loaded from the keepalived container,
and if it works in a non-selinux separated env, it doesn't work with
podman.

Change-Id: I71e638bedde3836e05cffab53ad80bfd35313a31
Related-Bug: 1794550

docker/services/keepalived.yaml

@@ -105,6 +105,12 @@ outputs:
               - KOLLA_CONFIG_STRATEGY=COPY_ALWAYS
             command: /usr/local/bin/kolla_start
       host_prep_tasks:
+        - name: load ip_vs module
+          import_role:
+            role: tripleo-module-load
+          vars:
+            modules:
+              - name: ip_vs
         - name: create persistent logs directory
           file:
             path: /var/log/containers/keepalived