Migrate the documentation system to use the ecoCode rule specification repo

[jhertout]

The repository https://github.com/green-code-initiative/ecoCode contains the rule specifications for all the plugins. It contains the definition of the android rules too. We must migrate our documentation system on the Android plugin to use the jar generated from this project (as it was done for others ecoCode plugins).

Must be "easily" done for Java and XML part of the plugin. May not be possible for Groovy rules (we will see later if it is the case).