Fix CSI security context and SecurityPolicyException

[ptrvsrg]

Summary

Aligns the CSI node plugin’s pod security with policy expectations and documents the exception in SPE.

Changes

• DaemonSet (node container): set allowPrivilegeEscalation: true (the default value is false, but if privileged is true, allowPrivilegeEscalation cannot be false), add capabilities.drop: [ALL] (this is requirement from admission policy engine).
• SecurityPolicyException: allow allowPrivilegeEscalation: true (node and node-driver-registrar containers has enabled allowPrivilegeEscalation)
• Tests: extend CSI node and SPE unittest suites to cover the new security context and SPE fields.

Why

Admission/policy checks may require explicit allowPrivilegeEscalation and a capability baseline (drop: ALL) even for privileged CSI node workloads; SPE must list the same allowances so the DaemonSet stays valid under the admission policy engine.