Prior to this commit, test bean overrides (for example, @MockitoBean,
@TestBean, etc.) eagerly honored the name of the annotated field as a
fallback qualifier, effectively ignoring @Primary and @Fallback
semantics for certain use cases.
This led to situations where a bean override for a test would select a
different bean than the core container would for the same autowiring
metadata.
To address that, this commit revises the implementation of
BeanOverrideBeanFactoryPostProcessor so that @Primary and @Fallback
semantics are consistently honored before attempting to use the
annotated field's name as a fallback qualifier.
Closes gh-34374