When importing a workflow then an included PostNotice Instruction and noticeBoardNames attribute should not be removed

Current Situation:
When importing a workflow that includes a PostNotice Instruction then the noticeBoardNames attribute and related array value is removed from the workflow.

Steps to reproduce:

• Create a Notice Board and workflow with a PostNotice Instruction.
• Export the folder containing the Notice Board and workflow including the PostNotice Instruction.
• Import the exported .zip archive file. The PostNotice Instruction and its noticeBoardNames attribute and related value will be removed from the workflow.

Desired Behavior:
When importing a workflow that includes a PostNotice Instruction then the noticeBoardNames attribute and its related array value should not be removed from the workflow.