'lang' param not bypassing languagePicker selection view

[cahirodoherty-learningpool]

Subject of the issue/enhancement/features

Passed 'lang' param is not bypassing the languagePicker language select screen

Your environment

Locally served adapt course

Steps to reproduce

Create a multilanguage course (including 'fr' for example) with languagePicker turned on
Serve the course locally and append index.html?lang='fr'

Expected behaviour

The languagePicker selection screen should be bypassed and the 'fr' version of the course should be presented

Actual behaviour

Language selection screen is presented.
_defaultLanguage is being set in the framework configModel, but the languagePicker attribute _showOnCourseLoad is true, so it is never taken into account

I propose that the '_activeLanguage' should be set on the configModel and the languagePicker should pick up on this. It will not exist as a config value if not passed as a param and therefore can be used to bypass the selection view