CA-394851: Update allowed operations on the cloned VBD

Default empty allowed_operations on a cloned VBD means that XenCenter
does not display the DVD option in the console tab for VMs cloned from
templates, for example.

Follow the practice in xapi_vbd, and update_allowed_operations immediately
after Db.VBD.create.

Signed-off-by: Andrii Sultanov <andrii.sultanov@cloud.com>

ocaml/xapi/xapi_vbd_helpers.ml

@@ -443,4 +443,5 @@ let copy ~__context ?vdi ~vm vbd =
     ~qos_algorithm_type:all.API.vBD_qos_algorithm_type
     ~qos_algorithm_params:all.API.vBD_qos_algorithm_params
     ~qos_supported_algorithms:[] ~runtime_properties:[] ~metrics ;
+  update_allowed_operations ~__context ~self:new_vbd ;
   new_vbd