[PVC] take prebuild, and write data, all subsequent data won't be recovered

[jenting]

Bug description

Enable feature flag PVC, and once we have ever taken prebuild, all the subsequent data won't be recovered from the VolumeSnapshot. The data is always recovered from the prebuild VolumeSnapshot.

Steps to reproduce

1. Enable feature flag PVC
2. Open the workspace, write some data (A), and close the workspace.
3. Manually trigger the prebuild, for example, gitpod.io/#prebuild/https://gitlab.com/gitpod-io/template-python-django
4. Open the workspace again, write some data (B), close the workspace and reopen it.
5. content B won't be recovered, but content A recovered. Double check the PVC's VolumeSnapshot, it always uses the prebuild VolumeSnapshot ID.

Workspace affected

No response

Expected behavior

No response

Example repository

No response

Anything else?

#7901

[jenting]

The PR is deployed by WebApp rather than Workspace, therefore, I changed the status from Awaiting Deployment to Done.