Clarify usage of @ConfigurationProperties annotated type declared with @Bean

[snicoll]

The new constructor binding is automatically applied when a constructor is present. If an application was relying on a custom constructor to inject other components, they'll be broken on upgrade as we'll try to call that constructor to bind properties.

Moving to @Bean will work but keeping @ConfigurationProperties on the type will not generate the expected metadata.

See spring-attic/spring-cloud-stream-binder-kafka#750 for a concrete example.

[snicoll]

This is now irrelevant as @ConstructorBinding is mandatory and the annotation processor uses this as the signal to harvest constructor parameters.