Launching from the editor can cause certain maps to become dirty and require saving and/or checkout

Using the launch option in the editor will cause some maps in the "List of maps to include in a packaged build" to become dirty and require checkout when in a project that is connected to source control. Another symptom of this bug is that the maps that are marked as dirty will remain so, even if saved, until the editor is reopened.

Regression?: Yes
Did not occur: 4.12.5 (3039270)
Occurs: 4.13 (3106830)

1. Create a new project
2. Add the new project to a Perforce repo and connect to source control in the editor
3. Create 2 new maps, save them, and add them to the repo
4. Add these 2 maps to the "List of maps to include in a packaged build" in Project Settings > Packaging and set one of them as the Game Default Map in Maps & Modes.
5. Use the Launch option to launch the game to any platform
   Result: One of the two maps will become dirty and require saving/checkout
   Expected: The launch should complete without anything else needing to be saved.