JIRA: https://jira.spring.io/browse/INT-3984
The `PropertySourcesPlaceholderConfigurer implements BeanFactoryPostProcessor, PriorityOrdered`
meaning that it is run before any other regular `BeanFactoryPostProcessor`,
like the `IntegrationConfigurationBeanFactoryPostProcessor` has been before.
With such an order any `BeanDefinition` declaration from the `IntegrationConfigurationBeanFactoryPostProcessor` process
ended up without `PP` resolutions.
* Rework `IntegrationConfigurationBeanFactoryPostProcessor` to the `BeanDefinitionRegistryPostProcessor`,
which makes it be loaded as early as possible. See `PostProcessorRegistrationDelegate`:
````java
// Now, invoke the postProcessBeanFactory callback of all processors handled so far.
invokeBeanFactoryPostProcessors(registryPostProcessors, beanFactory);
invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
````
* Modify `EnableIntegrationTests` and `ChannelSecurityInterceptorSecuredChannelAnnotationTests` to ensure that the change
meets the `PP` and `SpEL` resolutions during bean definition phase.
* Fix the timing issue in the `JdbcMessageStoreChannelIntegrationTests`
b469e62c8a