Description

Fix nil pointer panic when Central receives SensorEvent messages with unknown resource types from newer Sensor versions.

Root Cause

When Sensor 4.9.0 (or any newer version) sends events with resource types unknown to Central 4.8.4 (or older), the protobuf oneof resource field is unmarshaled as nil. Multiple code paths called GetEventTypeWithoutPrefix(msg.GetEvent().GetResource()) without checking for nil, causing panics in metrics collection and logging.

The issue was discovered in production logs showing 873 panic occurrences during cluster connections with Sensor 4.9.0 → Central 4.8.4 version mismatch.