Water body constructor dirties actor

Modify gets called from AWaterBody constructor:

   WaterSplineMetadata->Reset(3);
   WaterSplineMetadata->AddPoint(0.0f);
   WaterSplineMetadata->AddPoint(1.0f);
   WaterSplineMetadata->AddPoint(2.0f);

• Create a new map from the open world template.
• Add a ocean (or any water body to it)
• Save all.
• Run the resave packages commandlet on it.
  • "-run=resavepackages -OnlySaveDirtyPackages -mapsonly -packagesubstring="/maps/map_YourMap_wp"" to run on a specific map.