CAIQUM-5731: Rest call /api/datacenter/storage/volumes shows wrong values for qos policy-group extreme-fixed

Issue

The rest call towards AIQUM for a given volume that has extreme-fixed qos policy assigned, shows 0 on the max_throughput_mbps value.
For example for volume test1 the call:
https://10.216.26.28/api/datacenter/...mes?name=test1
returns:
.......
"qos": {
"policy": {
"key": "acf54920-27a0-11ee-8804-005056b1ebbe:type=qos_policy_group,qos_policy_group_uuid=b7189398-e572-48ab-8f69-82cd46580812",
"uuid": "b7189398-e572-48ab-8f69-82cd46580812",
"name": "extreme-fixed",
"_links": {
"self": {
"href": "/api/datacenter/storage/qos/policies/acf54920-27a0-11ee-8804-005056b1ebbe:type=qos_policy_group,qos_policy_group_uuid=b7189398-e572-48ab-8f69-82cd46580812"
}
},
"max_throughput_iops": 50000,
"max_throughput_mbps": 0,
"min_throughput_iops": 0
.......