Value of Global setting "convert.vmware.instance.to.kvm.extra.params.allowed.list" is not appened to the Virt-v2v tool

### problem

Value of Global settng "convert.vmware.instance.to.kvm.extra.params.allowed.list" is not appened to the Virt-v2v tool

### versions

ACS 4.22

### The steps to reproduce the bug

1. Enable the global setting "convert.vmware.instance.to.kvm.extra.params.allowed"

2. Set the convert.vmware.instance.to.kvm.extra.params.allowed to a value say -x

3. Import a vmware from kvm

4. In the import from vmware form, do not select the option "Pass extra parameters to the virt-v2v command on the conversion host"

5. Check the agent logs on the kvm host

The global setting value "extra.params" are not passed to the virt-v2v tool

```
2026-04-13 12:24:59,796 DEBUG [resource.wrapper.LibvirtConvertInstanceCommandWrapper] (AgentRequest-Handler-5:[]) (logid:565d9bad) Executing command [virt-v2v --root first -i ova /mnt/6f0e9b83-ab0d-3cc5-8ac6-189c672fe035/d1fa1750-df2d-44ba-90dc-1a39696137b5/i-2-16-VM/ -o local -os /mnt/6f0e9b83-ab0d-3cc5-8ac6-189c672fe035 -of qcow2 -on 5ed4eabd-058a-400e-a3c8-fa8c215bfb26 -v ].

```

6. The extra param value (-x) is only passed when it's mentioned in the "import from vmware form"

```

2026-04-13 12:31:32,208 DEBUG [resource.wrapper.LibvirtConvertInstanceCommandWrapper] (AgentRequest-Handler-4:[]) (logid:79bdffdc) Executing command [virt-v2v --root first -i ova /mnt/6f0e9b83-ab0d-3cc5-8ac6-189c672fe035/229a4c65-7ebd-42d4-90a2-e51fd2064973/i-2-16-VM/ -o local -os /mnt/6f0e9b83-ab0d-3cc5-8ac6-189c672fe035 -of qcow2 -on 1c906a30-86b1-442a-be0b-39f0cc65abcc -v x

2026-04-13 12:34:02,504 DEBUG [resource.wrapper.LibvirtConvertInstanceCommandWrapper] (AgentRequest-Handler-1:[]) (logid:3ae94f9c) Executing command [virt-v2v --root first -i ova /mnt/6f0e9b83-ab0d-3cc5-8ac6-189c672fe035/b4bc39ad-3065-42c2-b9a7-eec1f6c87454/i-2-16-VM/ -o local -os /mnt/6f0e9b83-ab0d-3cc5-8ac6-189c672fe035 -of qcow2 -on 4addaa01-58bc-43a4-a9d9-b030be5dde46 -v -x ].

```

### What to do about it?

Expected behaviour

The extra parameter value mentioned in the global setting should get populated in the import instance form and admin should be able to select the parameters which could be passed on the the virt-v2v tool

首先重現 VMware 匯入工作流程，並檢視顯示未帶有全域額外參數之 virt-v2v 命令的 agent log。追蹤 convert.vmware.instance.to.kvm.extra.params.allowed.list 的載入方式，以及匯入表單如何處理額外參數。當該設定填入表單，且在表單欄位未以其他方式選取時，所選值能夠傳遞至 virt-v2v，即表示完成。

由索引模型根據 Issue 內容生成。