Java: Fix alerting generation

[spinillos]

Maps were adding the import only for references and we weren't checking if a reference was an array. In this second case, we were setting values like Matchers and ObjectMatchers that are array aliases and they aren't allowed in Java.

Before:

public Matchers matchers;
public ObjectMatchers objectMatchers;

After:

public List<Matcher> matchers;
public List<List<String>> objectMatchers;