[BGP] ipv4routes can be defined for netconfig

In case of octavia, ipv4routes will be needed to connect to the
management network.

roles/ci_gen_kustomize_values/templates/bgp_dt01/network-values/values.yaml.j2

@@ -67,6 +67,13 @@ data:
         - end: {{ range.end }}
           start: {{ range.start }}
 {%    endfor %}
+{%    if network.tools.netconfig.ipv4_routes | default(false) %}
+        routes:
+{%      for route in network.tools.netconfig.ipv4_routes %}
+        - destination: {{ route.destination }}
+          nexthop: {{ route.gateway }}
+{%      endfor %}
+{%    endif %}
         cidr: {{ network.network_v4 }}
 {%      if network.gw_v4 is defined %}
         gateway: {{ network.gw_v4 }}