Fix 'server_default' parameter usage in models
Fix 'server_default' parameter usage in models

In ml2 models parameter 'default' is used for vnic_type, profile and
vif_details, but in migrations 27cc183af192_ml2_vnic_type,
157a5d299379_ml2_binding_profile and
50d5ba354c23_ml2_binding_vif_details is used 'server_default' parameter.
Usage 'default' and 'server_default' should be equal in models and
migration. So models in models is added 'server_default' parameter.

Partial-bug: #1295539

Change-Id: If6a17f381d2550daf64916ad3c1b120f41406d56

apporc/neutron,JioCloud/neutron,yuewko/neutron,sebrandon1/neutron,cisco-openstack/neutron,jumpojoy/neutron,mahak/neutron,cernops/neutron,wenhuizhang/neutron,noironetworks/neutron,mandeepdhami/neutron,mmnelemane/neutron,aristanetworks/neutron,jumpojoy/neutron,pnavarro/neutron,shahbazn/neutron,mattt416/neutron,virtualopensystems/neutron,infobloxopen/neutron,CiscoSystems/neutron,vivekanand1101/neutron,skyddv/neutron,antonioUnina/neutron,suneeth51/neutron,vveerava/Openstack,vveerava/Openstack,paninetworks/neutron,alexandrucoman/vbox-neutron-agent,virtualopensystems/neutron,SmartInfrastructures/neutron,eonpatapon/neutron,yuewko/neutron,sebrandon1/neutron,redhat-openstack/neutron,igor-toga/local-snat,SamYaple/neutron,klmitch/neutron,swdream/neutron,klmitch/neutron,chitr/neutron,CiscoSystems/neutron,mahak/neutron,bgxavier/neutron,silenci/neutron,SamYaple/neutron,gkotton/neutron,barnsnake351/neutron,blueboxgroup/neutron,mattt416/neutron,SmartInfrastructures/neutron,leeseuljeong/leeseulstack_neutron,neoareslinux/neutron,mandeepdhami/neutron,barnsnake351/neutron,asgard-lab/neutron,javaos74/neutron,Stavitsky/neutron,vveerava/Openstack,igor-toga/local-snat,NeCTAR-RC/neutron,suneeth51/neutron,pnavarro/neutron,projectcalico/calico-neutron,gkotton/neutron,leeseulstack/openstack,blueboxgroup/neutron,waltBB/neutron_read,MaximNevrov/neutron,yanheven/neutron,jerryz1982/neutron,virtualopensystems/neutron,CiscoSystems/neutron,JioCloud/neutron,gkotton/neutron,magic0704/neutron,bigswitch/neutron,asgard-lab/neutron,cernops/neutron,waltBB/neutron_read,miyakz1192/neutron,openstack/neutron,cloudbase/neutron-virtualbox,dims/neutron,skyddv/neutron,eayunstack/neutron,JianyuWang/neutron,bigswitch/neutron,takeshineshiro/neutron,projectcalico/calico-neutron,cisco-openstack/neutron,leeseulstack/openstack,glove747/liberty-neutron,magic0704/neutron,leeseulstack/openstack,sasukeh/neutron,wenhuizhang/neutron,shahbazn/neutron,paninetworks/neutron,Stavitsky/neutron,adelina-t/neutron,apporc/neutron,rdo-management/neutron,watonyweng/neutron,MaximNevrov/neutron,huntxu/neutron,takeshineshiro/neutron,glove747/liberty-neutron,chitr/neutron,cloudbase/neutron,watonyweng/neutron,NeCTAR-RC/neutron,dhanunjaya/neutron,eonpatapon/neutron,leeseuljeong/leeseulstack_neutron,Metaswitch/calico-neutron,rdo-management/neutron,jacknjzhou/neutron,adelina-t/neutron,huntxu/neutron,yanheven/neutron,infobloxopen/neutron,miyakz1192/neutron,openstack/neutron,dims/neutron,mmnelemane/neutron,dhanunjaya/neutron,leeseuljeong/leeseulstack_neutron,javaos74/neutron,wolverineav/neutron,noironetworks/neutron,bgxavier/neutron,jacknjzhou/neutron,silenci/neutron,jerryz1982/neutron,sasukeh/neutron,Metaswitch/calico-neutron,eayunstack/neutron,cloudbase/neutron-virtualbox,swdream/neutron,antonioUnina/neutron,JianyuWang/neutron,vivekanand1101/neutron,cloudbase/neutron,redhat-openstack/neutron,neoareslinux/neutron,aristanetworks/neutron,mahak/neutron,wolverineav/neutron,alexandrucoman/vbox-neutron-agent,blueboxgroup/neutron,openstack/neutron