ConfigTest - Virtual display python unit test (#1481) (#1528)

* -ConfigTest: Python unit test updated with additional virtual display tests.

Signed-off-by: Mei Chu <[email protected]>

* -ConfigTest: Addressed feedbacks.

Signed-off-by: Mei Chu <[email protected]>

* -ConfigTest: Addressing feedbacks on typos.
Signed-off-by: Mei Chu <[email protected]>

Co-authored-by: Patrick Hodoul <[email protected]>
Signed-off-by: Patrick Hodoul <[email protected]>

Co-authored-by: Mei Chu <[email protected]>

Author: hodoulp