TestOverrideMetadata was doing byName lookup by default, even without
a bean name. This makes writing tests that need to do by type lookup
way more complicated that it should.
This commit introduces DummyBean, that merely replaces two types with
hardcoded values. It also exposes the raw attribute of OverrideMetadata
and doesn't override anything from it to make sure the behavior is not
altered.
Closes gh-32982
45e9f04b57