"External System Import" of CSV should display the amount of Issues Updated

Problem Definition

When using the "External System Import" to update issues, the completion message doesn't display the amount of issues updated. It only displays Issues and Projects created.

For example, it will display:
"7 projects and 0 issues imported successfully!"
When it should be displaying:
"0 new issues created and 149 issues were updated across 7 projects."

Reason:
"External System Import" was designed as a migration tool

Suggested Solution

Add the updated amount of issues to the message.

Workaround

Use the "Import Issues from CSV" option to update issues.
JRA-39749 - "Import Issues from CSV" button doesn't work in the same way as "External System Import"