I find some code examples here about enabling APOC in embedded neo4j.
It is something like that i need to register the procedure's class. (but lack of description. wonder if there is official tutorial of that)
I have added this in my pom.xml : http://mvnrepository.com/artifact/org.neo4j.procedure/apoc/3.3.0.4
And I guess there should be a class like apoc.util.Md5
to register, but it is seem no.
On an embedded database you need to register your functions and procedures, can you try this :
(GraphDatabaseAPI) getDatabase()).getDependencyResolver().resolveDependency(Procedures.class).registerFunction(apoc.util.Utils.class)
Cheers