You are already having a job as automation test engineer and now want to swap it for a better proposition. The data science / analytics is an emerging area and there are good opportunities to make a career in it as many big companies and multinationals are giving a thrust in this area to adopt it for management information and decision making process. It is already expanding at a fast pace and going to be a vast field soon. In this situation, I feel, that this is a right decision to go for this swap and undergo some good data science / analytics course before entering the industry in a suitable position.
In addition to the two good sources which you have mentioned (Great Lakes and Praxis), there are some other good ones in this area from where you can learn the intricacies of Data Science / Analytics. These are -
1. Certificate Program in Data Science & Engineering (Big Data & Visual Analytics) By SP Jain School of Global Management.
2. Post-Graduate Diploma in Business Analytics (Jointly offered By IIM Calcutta, ISI Kolkata, IIT Kharagpur).
3. Postgraduate Diploma in Data Science by Jigsaw Academy.
4. Post-Graduate Program in Data Science By Great Learning.
5. M.Tech Data Science & Artificial Intelligence
By NMIMS's Mukesh Patel School of Technology Management & Engineering.
6. Big Data Analytics course By Goa Institute of Management.
7. Leadership Through Analytics and Decision Sciences By T. A. Pai Management Institute.
8. MBA in Data Sciences & Data Analytics by Symbiosis Centre for Information Technology.