[2D][Sprite Atlas][PSB Importer] Sprites imported by PSB Importer not packed in atlas

When packing sprites imported through PSB importer, sprite atlases do not update to new packing list (it would revert to packing list of the first time it was packed)
Addition of non-PSB Imported sprites will update atlas to the correct packing list

Repo Steps:
1. Open sample project
2. Create new sprite atlas
3. Refer to attached video to reproduce issue

Expected Result: Atlases are updated when packing sprites imported through PSB importer
Actual Result: Atlases are updated not when packing sprites imported through PSB importer