[DSG] RHODS admins are not warned when usage exceeds 90% or 100% for PVCs created by Data Science Projects

Description of problem:

Prometheus usually has an alerts checking for PVC usage and triggering when oen PVC is filled above 90% or at 100%

But it works only for PVC created by the classic Spawner and not for DSG.

Prerequisites (if any, like setup, operators/versions):

Create a DS Project from Dashboard UI

Create a workbench with a PVC (1GB size for convenience of testing) from Dashboard UI 

Steps to Reproduce

1. Launch the workbench
2. fill in the underlying PVC above 90% or at 100% (example code)
3. check prometheus alerts are not firing (redhat-ods-monitoring namespace)

Actual results:

no alerts defined in prometheus to check PVC usage above 90% and 100%

Expected results:

alerts defined in prometheus to check PVC usage above 90% and 100%

Reproducibility (Always/Intermittent/Only Once):

Always

Build Details:

RHODS v1.19.9-10

Workaround:

Additional info: