SystemEventLogs: Audit enabled/disabled events not generated properly

Build: 7.1.0-1515

Steps: (All through UI)

1. Single node cluster, load 'travel-sample` bucket
2. Add second node with index+n1ql services
3. Goto Settings -> Audit
4. Enable audit logs using the toggle button and press 'Save' button
5. Disable audit logs using the toggle button and press 'Save' button

Observations:

1. After step#4, 'AuditEnabled # 9216' event is missing in the sys_event logs
2. After disabling the audit logging, we can only see the event_id=10243 for view engine settings changed with extra_attr (audit_enabled,false). There is no audit_disabled log_here.
3. Now again pressing the 'Save' button in UI without any changes (Audit is still disabled), Audit disabled event is generated this time.

Expected behavior:

• Step#4 should generate audit enabled log followed by settings changed
• Step#5 should generate audit disabled event without any extra step