ceph: updated PVC utilizaztion alerts

[anmolsachan]

Backport PR for #5682

Updated warning and critical alerts for all the PVC's created by rook-ceph provisioners. Added the recommendation to expand the PVCs.

Closes: BZ1849717
Signed-off-by: Anmol Sachan anmol13694@gmail.com

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Checklist:

• Commit Message Formatting: Commit titles and messages follow guidelines in the developer guide.
• Skip Tests for Docs: Add the flag for skipping the build if this is only a documentation change. See here for the flag.
• Skip Unrelated Tests: Add a flag to run tests for a specific storage provider. See test options.
• Reviewed the developer guide on Submitting a Pull Request
• Documentation has been updated, if necessary.
• Unit tests have been added, if necessary.
• Integration tests have been added, if necessary.
• Pending release notes updated with breaking and/or notable changes, if necessary.
• Upgrade from previous release is tested and upgrade user guide is updated, if necessary.
• Code generation (make codegen) has been run to update object specifications, if necessary.

[skip ci]

[richardelling]

Why do we need to warn when an rbd is full? Isn't that an expected condition for rbds?

[anmolsachan]

Why do we need to warn when an rbd is full? Isn't that an expected condition for rbds?

The alert is for the PVC's provisioned from RBD provisioner. If the PVC is nearing full, the alert will notify the user, so that they can delete some stale data or expand the PVC. It is not necessary that the RBD pool might be full