Added limited disk cache for android template.

@drmillan I added two classes to complete a bit more the cache stuff functionality! =)
They are related to disk limit.

BTW, following your guidelines, I forked your repo, created a branch and so on. But I dont know why the branch is displayed in your repo instead of mine. Is it correct? or should I see the branch and PR (suggestion) on my github webpage repo instead?

Sorry If i did something wrong. 

@mrmans0n @kikogo @juanmatm82 @luismacb @awayo  Please, could take a look? Thanks in advance!
This shouldn't have authorship. They should comply with the other cache classes in this package. For example, in UnlimitedDiskCache the header is:
```java
/**
 * Class to save contents to disk. As we do not know if the stuff stored is a DTO or how
 * can we serialize/deserialize it, we need the DataTransferObjectJSONMarshallingInterface
 *
 * @author Service Generator
 *
 * Generated Class - DO NOT MODIFY
 */
```