Gather extra networking facts for keepalived

By default keepalived pingable check tries to verify the gateway which
in it's turn requires to have appropriate facts defined.

At the moment re-running haproxy playbook as a standalone instance
when facts are outdated will lead to re-configuration of keepalived
to check 127.0.0.1 as a track script.

So we gather extra network facts to identify the gateway for
pingable script.

Change-Id: I4e72e81d05d8d70e76730a46687dd06f3e66ebc6

playbooks/haproxy-install.yml

@@ -19,6 +19,14 @@
   tasks:
     - name: Gather additional facts
       include_tasks: "common-tasks/gather-hardware-facts.yml"
+      vars:
+        deployment_extra_facts_filter:
+          - "ansible_processor_*"
+          - ansible_default_ipv4
+        deployment_extra_facts_subset:
+          - '!all'
+          - hardware
+          - network
       when: osa_gather_facts | default(True)
   tags:
     - always