BuildGraph build fails if Use Unity Build and Use PCH Files are set to false in BuildConfiguration.xml

Using BuildGraph to create a local binary build of the engine fails if the BuildConfiguration.xml file has bUseUnityBuild and bUsePCHFiles both set to false. The build fails due to some missing Json includes.

1. Open the BuildConfiguration.xml file and set it to not use unity build or PCH files.

   <?xml version="1.0" encoding="utf-8" ?>
    <Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">
        <BuildConfiguration>
            <bUseUnityBuild>false</bUseUnityBuild>
            <bUsePCHFiles>false</bUseSharedPCHs>
        </BuildConfiguration>
    </Configuration>
   

2. Navigate to the Engine\Build\Batchfiles folder of your Engine installation and open a command prompt window there.
3. Run the following command: runuat.bat BuildGraph -Script=Engine\Build\InstalledEngineBuild.xml -target="Build Tools CS; Compile UnrealHeaderTool Win64; Compile UE4Editor Win64; Compile UE4Game Win64" -verbose=VeryVerbose -Clean -p4 -UseLocalBuildStorage -set:WithDDC=false -set:HostPlatformOnly=true -ForceNonUnity -Licensee -Compile

RESULT:
The build will fail with several undeclared identifier errors (see attached log).

EXPECTED:
The build completes successfully.

WORKAROUND:
Adding the following includes to Engine\Plugins\Online\OnlineSubsystem\Source\Private\OnlineSubsystemImpl.cpp allows the build to complete successfully:

#include "Dom/JsonObject.h"
#include "Dom/JsonValue.h"
#include "Serialization/JsonReader.h"
#include "Serialization/JsonSerializer.h"