JIRA: https://jira.spring.io/browse/INT-3664
Since all metrics are already direct for the integration components, we don't do any proxying from `IntegrationMBeanExporter`,
and even any other adjustments during BPP phases. Hence this stuff is already redundant for `IntegrationMBeanExporter`.
In addition this change fix the `early access to the BeanFactory from BPP` issue.
INT-3664: Address PR comments
Doc Polish
INT-3664: Polishing according the SF changes to the `PostProcessorRegistrationDelegate$BeanPostProcessorChecker`
0f05512e9a