Unable to package Engine plugins

Engine plugins included in the Engine are unable to be packaged. Attempting to package one results in the package process failing with an error stating that all source files must include the same precompiled header first.

Setting the PCHUsage property for each module in the plugin to UseExplicitOrSharedPCHs allows the plugin to be packaged.

1. Open any project in the Editor.
2. Go to Edit -> Plugins -> Built-in -> 2D
3. Click the Package link for Paper 2D.
4. Select a folder to package the Paper 2D plugin into.

RESULT:
The package process fails with the following error: UnrealBuildTool: ERROR: All source files in module "Paper2D" must include the same precompiled header first.

EXPECTED:
The Paper 2D plugin packages successfully.

WORKAROUND:
Add PCHUsage = ModuleRules.PCHUsageMode.UseExplicitOrSharedPCHs; at the top of the Build.cs file for each module in the plugin, above any include paths or dependencies for the plugin.