Use global to represent OS-TRUST:trust
Use global to represent OS-TRUST:trust

When sending a notification a resource_type is required, such as a
'user', 'project', or 'OS-TRUST:trust'. This value is consistent between
operations so it can be stored in a class global variable.

Change-Id: I1a9e66330d980e13d306f4d6a6c0f248e75a858e

rushiagr/keystone,maestro-hybrid-cloud/keystone,ilay09/keystone,nuxeh/keystone,jonnary/keystone,ging/keystone,maestro-hybrid-cloud/keystone,JioCloud/keystone,dims/keystone,mahak/keystone,MaheshIBM/keystone,ajayaa/keystone,promptworks/keystone,UTSA-ICS/keystone-kerberos,ilay09/keystone,vivekdhayaal/keystone,takeshineshiro/keystone,jumpstarter-io/keystone,dstanek/keystone,jumpstarter-io/keystone,mahak/keystone,JioCloud/keystone,rajalokan/keystone,jonnary/keystone,promptworks/keystone,ilay09/keystone,openstack/keystone,UTSA-ICS/keystone-kerberos,idjaw/keystone,openstack/keystone,MaheshIBM/keystone,ajayaa/keystone,reeshupatel/demo,cernops/keystone,jumpstarter-io/keystone,rajalokan/keystone,nuxeh/keystone,klmitch/keystone,reeshupatel/demo,vivekdhayaal/keystone,takeshineshiro/keystone,nuxeh/keystone,vivekdhayaal/keystone,dims/keystone,rushiagr/keystone,promptworks/keystone,blueboxgroup/keystone,roopali8/keystone,himanshu-setia/keystone,himanshu-setia/keystone,idjaw/keystone,dstanek/keystone,openstack/keystone,rajalokan/keystone,ging/keystone,mahak/keystone,roopali8/keystone,rodrigods/keystone,reeshupatel/demo,jamielennox/keystone,jamielennox/keystone,dstanek/keystone,klmitch/keystone,rodrigods/keystone,cernops/keystone,blueboxgroup/keystone,rushiagr/keystone