Order paid subscriber fails due to interface name InvoiceInterface

Problem/Motivation

When order is paid, the order paid event subscriber is called, but it fails due to incorrect interface name in condition.

Steps to reproduce

Complete the order checkout for invoice.
Order status is correctly changed to completed.
Invoice status is still not changed to paid.

Proposed resolution

Fix the instance name so condition is correct & it does not skip the invoice transition.

User interface changes

None.

API changes

None.

Data model changes

None.