Fixes handling of arrays in XML to JSON conversion

The xml to json method in compute/xml/common.py has
an option to specify which XML elements shall be translated
to a list rather than a dict.
The current implementation though applies only for the
first level of elements and it's not passed down to
children elements.

Closes-Bug: #1267867
Change-Id: I70f6b95fbeac2a9e28e935e506ba43d183690994
Merge "Fixes handling of arrays in XML to JSON conversion"