Do not reset state file in PulseEngineDriver if the StreamingAssets are missing
Tested with the initial asset store release.
When the asset store package gets downloaded, the state files in the examples are reset due to : https://gitlab.kitware.com/physiology/PulseUnityAsset/blob/a61c50f2/PulsePhysiologyEngine/Scripts/Editor/PulseEngineDriverEditor.cs#L61