[BUG] vcsim: ReconfigVM_Task incompletely updates disk's capacity

[Syuparn]

Describe the bug
A clear and concise description of what the bug is.

VirtualDisk has two fields which show the disk's capacity, capacityInKB and capacityInBytes.
ReconfigVM_Task allows either one (or both) and reconfigured disk will have both fields updated.
However, vcsim only updates the specified field and the other one remains 0.

To Reproduce

1. run vcsim without any options
2. exec govc command below

$ govc vm.disk.create -vm DC0_H0_VM0 -name DC0_H0_VM0/disk2 -size 1G
[24-06-22 21:52:06] Creating disk
# fetch created capacity fields
$ govc device.info -json -vm DC0_H0_VM0 disk-202-1 | jq ".Devices[] | {CapacityInKB, CapacityInBytes}"

Expected behavior

Both fields represent 1GB.

$ govc device.info -json -vm DC0_H0_VM0 disk-202-1 | jq ".Devices[] | {CapacityInKB, CapacityInBytes}"
{
  "CapacityInKB": 1048576,
  "CapacityInBytes": 1073741824
}

Affected version

• vcsim: 0.28.0

Screenshots/Debug Output

CapacityInBytes is not set.

$ govc device.info -json -vm DC0_H0_VM0 disk-202-1 | jq ".Devices[] | {CapacityInKB, CapacityInBytes}"
{
  "CapacityInKB": 1048576,
  "CapacityInBytes": 0
}

Additional context
Add any other context about the problem here.

If capacityInBytes and CapacityInKB in ReconfigVM_Task represent different capacity, CapacityInBytes takes precedence (in vSphere 7.0u3).

disk.CapacityInBytes = 512 * 1024
disk.CapacityInKB = 1024

err = vm.AddDevice(ctx, disk)
// ...

$ govc device.info -json -vm myvm disk-1000-1 | grep CapacityIn
      "CapacityInKB": 512,
      "CapacityInBytes": 524288,