When custom validations are made and Xray cannot know about it, the user should be able to choose between JIRA create issue screen and Xray create issue screen

Sometimes, validations can be made without using required fields. For example, the user can add a script validation. In those cases, the user must be able to select between the JIRA issue create screen and the Xray create screen, or at least be able to add the validated field to the Xray Screen. An example of where this should be possible is on create a Test Execution from Test Plan.