NetApp Volume doesn't set export policy at first http request

After tested, I found NetApp Volume doesn't set export policy at first http request while "ProtocolTypes" is set and the all values of "Cifs/Nfsv3/Nfsv41" of "ExportPolicyRule" are "false". And then I sent http request again with same http request body, export policy can be set correctly. I assume it should set correctly at first time.

First http request:
```
PUT https://management.azure.com/subscriptions/xx-xx-xx-xx/resourceGroups/example-resources2/providers/Microsoft.NetApp/netAppAccounts/example-netappaccount2/capacityPools/example-netapppool2/volumes/example-netappvolume2

{
"location": "westeurope",
"properties": {
"creationToken": "my-unique-file-path",
"serviceLevel": "Premium",
"usageThreshold": xxx,
"exportPolicy": {
"rules": [
{
"ruleIndex": 1,
"unixReadOnly": false,
"unixReadWrite": false,
"cifs": false,
"nfsv3": false,
"nfsv41": false,
"allowedClients": "10.0.2.2,10.0.2.3,10.0.2.1"
}
]
},
"protocolTypes": [
"NFSv3"
],
"subnetId": "/subscriptions/xx-xx-xx-xx/resourceGroups/example-resources2/providers/Microsoft.Network/virtualNetworks/example-virtualnetwork2/subnets/example-subnet2"
},
"tags": {}
}
```

Result:

Second http request:
```
PUT https://management.azure.com/subscriptions/xx-xx-xx-xx/resourceGroups/example-resources2/providers/Microsoft.NetApp/netAppAccounts/example-netappaccount2/capacityPools/example-netapppool2/volumes/example-netappvolume2

{
"location": "westeurope",
"properties": {
"creationToken": "my-unique-file-path",
"serviceLevel": "Premium",
"usageThreshold": xxx,
"exportPolicy": {
"rules": [
{
"ruleIndex": 1,
"unixReadOnly": false,
"unixReadWrite": false,
"cifs": false,
"nfsv3": false,
"nfsv41": false,
"allowedClients": "10.0.2.2,10.0.2.3,10.0.2.1"
}
]
},
"protocolTypes": [
"NFSv3"
],
"subnetId": "/subscriptions/xx-xx-xx-xx/resourceGroups/example-resources2/providers/Microsoft.Network/virtualNetworks/example-virtualnetwork2/subnets/example-subnet2"
},
"tags": {}
}
```

Result: