Goal

• CNV takes VM snapshots without savevm or migrating to file. Only the disk state and files associated with a VM (like the vTPM state) are saved. Currently it copies the vTPM's state file but the on-disk state may be outdated or inconsistent.
• Provide a way for CNV to save a consistent snapshot of the vTPM state. 

Acceptance criteria

• Saving and restoring the vTPM state works.

This story is about investigating how to flush the vTPM state to disk so that CNV can copy a consistent snapshot of the state. See CNV-59488 for the larger context.