Previously, if a managed bean had only one non-default constructor, we
should still annotate it with `@Autowired` to properly use constructor
injection. Not doing so resulted in an error as the container was
trying to call the default (non-existing) constructor.
This commit updates this behaviour to automatically applyed the
autowiring semantic to any bean that has only one constructor. As
before, if more than one constructor is defined, `@Autowired` must be
specified to teach the container the constructor it has to use.
Issue: SPR-12278