[2121320] Negative values in migration metrics

Description of problem:
Migration metrics "kubevirt_migrate_vmi_pending_count",kubevirt_migrate_vmi_scheduling_count" and "kubevirt_migrate_vmi_running_count" show negative values on migrating the VM

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. create a VM
2. Migrate the VM
3. Observe the metrics' values

Actual results:
Negative values are observed

Expected results:
No negative values

Additional info: