Only run ovn_bgp_agent tasks from the tripleo_frr role

Currently simply importing the tripleo_frr role would override the
frr configuration, breaking per-role parameters and such.
By running only the necessary tasks we effectively split frr vs
ovn_bgp_agent configuration steps so they do not clash with each other.

Change-Id: I3e8020457be89d7198b3cbff201e9470ffcb031b

deployment/ovn/ovn-bgp-agent-container-ansible.yaml

@@ -240,6 +240,7 @@ outputs:
         - name: Configure Ovn Bgp Agent
           import_role:
             name: tripleo_frr
+            tasks_from: ovn_bgp_agent
           vars:
             tripleo_frr_ovn_bgp_agent_internal_tls_enable: {get_param: EnableInternalTLS}
             tripleo_frr_ovn_bgp_agent_driver: {get_attr: [RoleParametersValue, value, ovn_bgp_agent_driver]}