CLOUDSTACK-5278 Fixed cleaning up egress default rules on VR and SRX

   1. Egress default policy rules is send to the firewall provider. It is up to the
    provider to configure the rules.
   2. The default policy rules are send for both allow and deny default policy.
   3. On network shutdown rules for delete are send.
   4. For VR and SRX, by default deny the traffic. So no default rule to deny traffic is required.
put CS/XS plugin log into seperate directory