Paper2D Sprite doesn't cook deterministically

The "DummySprite" asset in Plugins/Paper2D doesn't cook deterministically, and as such is always included in patches.

1. Start with ShooterGame or QAGame project in 4.15 or 4.16
2. Follow the steps in Releasing Your Project
3. Follow the steps in Patching
4. Unpak the .pak file in Saved\StagedBuilds\WindowsNoEditor*projectname*\content\paks with the command UnrealPak.exe pack-name.pak -extract path\to\extract\to\
5. Notice although this file hasn't changed, it is included in the path in the extracted location path\to\extract\to\Engine\Plugins\2D\Paper2D\Content\DummySprite.uexp