Description of problem:
Can't get correct cluster size when vol-create-from with an cluster size in target volume

Version-Release number of selected component (if applicable):
libvirt-7.4.0-1.module+el8.5.0+11218+83343022.x86_64
qemu-kvm-6.0.0-18.module+el8.5.0+11243+5269aaa1.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Prepare a dir pool and a volume xml.

1. virsh pool-list --all
   Name State Autostart
   -------------------------------
   default active yes
2. cat volume.xml
   <volume>
   <name>cluster.img</name>
   <key>/var/lib/libvirt/images/cluster.img</key>
   <capacity unit="G">2</capacity>
   <allocation>294912</allocation>
   <target>
   <path>/var/lib/libvirt/images/cluster.img</path>
   <format type='qcow2'/>
   </target>
   </volume>

2. Create a volume with vol-create.

1. virsh vol-create --pool default volume.xml
   Vol cluster created from volume.xml
2. virsh vol-list default
   Name Path
   --------------------------------------------------------
   cluster.img /var/lib/libvirt/images/cluster.img

3. Vol-create-from target volume with cluster size.

1. cat dest-volume.xml
   <volume>
   <name>cluster1.img</name>
   <key>/var/lib/libvirt/images/cluster1.img</key>
   <capacity unit="G">2</capacity>
   <allocation>294912</allocation>
   <target>
   <path>/var/lib/libvirt/images/cluster1.img</path>
   <format type='qcow2'/>
   </target>
   <clusterSize unit='KiB'>512</clusterSize>
   </volume>
2. virsh vol-create-from default dest-volume.xml cluster.img --inputpool default
   Vol cluster1.img created from input vol cluster.img

4. Check the cluster size in the new volume.

1. virsh vol-dumpxml --pool default cluster1.img | grep clusterSize
   ------Can't get the cluster size

1. systemctl restart libvirtd
2. virsh vol-dumpxml --pool default cluster1.img | grep clusterSize
   <clusterSize unit='B'>65536</clusterSize>
   ------Get the incorrect cluster size even though restart the libvirtd

Actual results:
As above step 4.

Expected results:
Can get the correct cluster size.

Additional info: