relocate os_compute_api:servers:discoverable
relocate os_compute_api:servers:discoverable

move os_compute_api:servers:discoverable to other
policy defined position to make them easier
to be recognized and used by end user.

Change-Id: I5fc4b55418f187817e81343e9224b731f8eea5e2

rajalokan/nova,dims/nova,mahak/nova,Juniper/nova,klmitch/nova,BeyondTheClouds/nova,cernops/nova,klmitch/nova,mikalstill/nova,rajalokan/nova,jianghuaw/nova,gooddata/openstack-nova,mahak/nova,NeCTAR-RC/nova,zhimin711/nova,jianghuaw/nova,gooddata/openstack-nova,openstack/nova,rahulunair/nova,cyx1231st/nova,gooddata/openstack-nova,vmturbo/nova,klmitch/nova,Juniper/nova,vmturbo/nova,hanlind/nova,hanlind/nova,CEG-FYP-OpenStack/scheduler,rajalokan/nova,Juniper/nova,sebrandon1/nova,cloudbase/nova,phenoxim/nova,openstack/nova,bigswitch/nova,cloudbase/nova,cernops/nova,cloudbase/nova,gooddata/openstack-nova,alaski/nova,klmitch/nova,phenoxim/nova,openstack/nova,NeCTAR-RC/nova,dims/nova,BeyondTheClouds/nova,hanlind/nova,Juniper/nova,rahulunair/nova,jianghuaw/nova,CEG-FYP-OpenStack/scheduler,alaski/nova,mikalstill/nova,sebrandon1/nova,sebrandon1/nova,BeyondTheClouds/nova,rahulunair/nova,cernops/nova,vmturbo/nova,mikalstill/nova,bigswitch/nova,rajalokan/nova,jianghuaw/nova,vmturbo/nova,cyx1231st/nova,mahak/nova,zhimin711/nova