Understand if we can detect ovn-controller cpu starvation using existing metric

We need to understand under what conditions metric ovn_controller_packet_in_drop may increment.

We understand currently that when cpu starvation occurs for ovn controller, this metric may increment.

Investigate how this may occur, test it,  document how you triggered it, and suggest a new alert to capture when this may occur consistently.

Understanding this metric (and follow on alert) will help highlight when customers worker nodes are overloaded and networking is degraded impacting the user exp.