Adds forward to enrolment widget if on Android

Instead to forwarding to the testbed page the enrolment
widget will be shown on last step of enrolment process.

Jira issue: WP-947
Adds GET parameter to signalize the widget entry mode

Jira issue: WP-947
Merge pull request #568 from mlasak/WP-947

Adds forward to enrolment widget if on Android