Issue Summary

A NullPointerException occurs during the re-run of a migration using the MultiTransferDiscoverableListener interface. This error arises in the onStartAppMigration method and also present in the latest version of the atlassian-app-cloud-migration-listener dependency (1.6.1).

Steps to Reproduce

1. Implemented the new MultiTransferDiscoverableListener interface
2. Try to re-run the migration

Expected Results

The re-run of a migration using the MultiTransferDiscoverableListener interface should execute without errors.

Actual Results

When performing a re-run of a migration using the MultiTransferDiscoverableListener interface, a NullPointerException occurs in the onStartAppMigration method.

Sent listener errored notification for transferId: de1a84e0-e395-44d0-9111-a9133288b18b with transfer error: TransferError(exceptionType=java.lang.NullPointerException, safeStackTrace=cloud.atlassian.logmon.laas.api.PrivacySafeException: Privacy-safe boxing of a java.lang.NullPointerException
	at com.atlassian.migration.app.MultiTransferDiscoverableListenerProxy.onStartAppMigration(MultiTransferDiscoverableListenerProxy.kt:109)
	at com.atlassian.migration.app.AbstractCloudMigrationRegistrar.executeRerun(AbstractCloudMigrationRegistrar.kt:282)
	at com.atlassian.migration.app.AbstractCloudMigrationRegistrar.executeTransfer(AbstractCloudMigrationRegistrar.kt:180)
	at com.atlassian.migration.app.DefaultRegistrar.runJob(DefaultRegistrar.java:96)

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available