Fix compile and python errors from the export script

[spham-amzn]

Fixes the following build errors when building against the latest o3de development (commit f35b02e8dc78084eae621ff9cea898daa493e553)

In file included from /data/workspace/o3de-multiplayersample/build/tools/External/Gem-f6f5d0f3/Code/CMakeFiles/MultiplayerSample.dir/Unity/unity_0_cxx.cxx:5:
/data/workspace/o3de-multiplayersample/Gem/Code/Source/UserSettings/MultiplayerSampleUserSettings.cpp:264:32: error: no member named 'm_rayTracing' in 'AZ::Render::SSROptions'
                    ssrOptions.m_rayTracing = (reflectionType == SpecularReflections::ScreenSpaceAndRaytracing) ? 
                    ~~~~~~~~~~ ^

Also fixes the following python error during the project export script

 File "/data/workspace/o3de-multiplayersample/ExportScripts/export_mps.py", line 248, in <module>
    export_multiplayer_sample(ctx=o3de_context,
  File "/data/workspace/o3de-multiplayersample/ExportScripts/export_mps.py", line 101, in export_multiplayer_sample
    launcher_type |= exp.LauncherType.HEADLESS
  File "/root/.o3de/Python/packages/python-3.10.13-rev2-linux/python/lib/python3.10/enum.py", line 437, in __getattr__
    raise AttributeError(name) from None
AttributeError: HEADLESS

TypeError: bundle_assets() got an unexpected keyword argument 'selected_platform