Custom single/multi selection fields doesn't indexed for search.

Hi everyone!
Found some bug with search indexing for custom single/multi selection fields in core.

Added the new field to Article’s attributes, let’s say “Country” (type: MULTI SELECTION, Entity: Country - Shopware\Models\Country\Country)
The new Field added to search index by custom “SearchTermQueryBuilder”

public function buildQuery(ShopContextInterface $context, $term)
        $query = $this->decoratedQueryBuilder->buildQuery($context, $term);
        $matchQuery = new MultiMatchQuery(['attributes.core.countries'], $term);
        $query->add($matchQuery, BoolQuery::SHOULD);
        return $query;

In Article details template avaibale only string with keys:    countries = " |2|3|4|"
ProductProvider also got  |2|3|4| in Article structure, and this wrong data transfered to Search index.

Expected:  countries = “value value value-n …”

Does it possible transfer to search index content, not just KEYs from referenced Models?

Many thanks and have a good day.