Update Journey Version Step Events XDM Mixin to add attributes related to exit criteria

## What are the schemas that are affected by the issue
https://github.com/adobe/xdm/blob/master/extensions/adobe/experience/journeyOrchestration/stepEvents/journeyStepEventCommonFieldsMixin.schema.json

## What are examples of products that are impacted by the issue
Journey Orchestration, Customer Journey Management

Start by reviewing journeyStepEventCommonFieldsMixin.schema.json and identify which exit-criteria attributes are required for Journey Orchestration and Customer Journey Management. The issue is complete when the agreed attributes are represented in that schema and the affected examples or validation expectations are addressed.

Written by the indexing model from the issue text.