Query for a dictionary key inside a collection of mixed doesn't find matches

[nirinchev]

I have the following test case:

realm.write(() {
  first = realm.add(AnythingGoes(
      oneAny: RealmValue.from([
    1,
    'a',
    {'foo': 'bar'}
  ])));

  second = realm.add(AnythingGoes(
      oneAny: RealmValue.from([
    2,
    {'foo': 'baz'}
  ])));

  third = realm.add(AnythingGoes(
      oneAny: RealmValue.from([
    3,
    'c',
    {
      'foo': {'child': 5},
      'bar': 10
    },
    3.4
  ])));
});

final dictionaryInListQuery = realm.query<AnythingGoes>("oneAny[*].foo BEGINSWITH 'ba'");
expect(dictionaryInListQuery, unorderedMatches([first, second]));

oneAny is a mixed property and I create 3 objects where oneAny contains a list and one of the elements in the list is a dictionary that has the key foo. Two of the objects have values for foo that start with ba, so I expect the query to find them, but it returns an empty collection. Is my query wrong or is there a bug with the implementation of queries that traverse collections in mixed? Based on this document, it appears like this type of query is supported.

[jedelbo]

Fixed by #7315