The docs had three things wrong:
1. The server status would be VERIFY_RESIZE, not VERIFY_RESIZED.
2. The RESIZED value is on the OS-EXT-STS:vm_state field, not
vm_status.
3. The migration record status must be "finished", which is what
gets set on the migration record in the _finish_resize() method
in ComputeManager and used in the comptue API.confirm_resize()
method. "confirming" status is what the API sets the migration
record to before casting to nova-compute to finish the
confirmation.
Stepping back, this is too many conditionals for what is really
needed. So rather than fix all three items individually, this
change simply fixes the first one and removes the other two since
the 'status' is based on the 'vm_state' internally, and a non-admin
user cannot list migrations anyway, and the _finish_resize()
method sets the migration status *before* the vm_state.
Closes-Bug: #1764878
Change-Id: Ib751686880ee824cf0693a649f47c828f515b471