SOC-4162: [Experience] Wrong date validation when still at a position.

Problem analysis
	- When ending date gets the value "Still in this position", its value is null.

Fix description
	- Verify end date is not null and not empty before parsing date value
	- Do not check any validation else when there is a wrong date time format
Merge commit '1e45a9e6e0d6ca3fe3952d3beea9d5fe462a0cb3' into HEAD