Add information on running android tests and collecting data

Added instructions on running the tests for android.

Couple of questions is there enough information for someone contributing to be able to run the tests?
and is the style and formatting in keeping with the rest of the doc
I think this para generally makes sense but you may want to rewrite it. e.g. "The test results are in the same format as those generated by the ant junit task."

Also some detail about the location and naming of the xml file might be useful.