Share the system-probe socket when oom_kill or tcp_queue_length checks are enabled

[L3n41c]

What does this PR do?

Share the system-probe socket with the core agent when the oom_kill or tcp_queue_length checks are enabled.

Motivation

This is a followup of #642 to fix the activation of oom_kill and tcp_queue_length checks.

Additional Notes

Describe your test plan

Start a datadog agent with a manifest like:

apiVersion: datadoghq.com/v2alpha1
kind: DatadogAgent
metadata:
  name: datadog
spec:
  global:
    credentials:
      apiSecret:
        secretName: datadog-secret
        keyName: api-key
      appSecret:
        secretName: datadog-secret
        keyName: app-key
  features:
    oomKill:
      enabled: true
    tcpQueueLength:
      enabled: true

and an agent version that contains DataDog/datadog-agent#14332 and check that the oom_kill and tcp_queue_length checks are correctly scheduled in the core agent.