0 for min_children option in has_child query doesn't make sense, because:

1. It is ambiguous. Does it mean to match only parents that either have children matching the specified constraints or no have no children at all.
2. It currently behaves as a value of 1, that is if there is no at least 1 child matching a specified constrained, a parent document is not returned.

For these reasons, we should make 0 value as invalid value.

Related #21224