Extend BuildPlayerProcessor to receive callbacks during a player build.
Additional resources: IFilterBuildAssemblies, IPostBuildPlayerScriptDLLs, IUnityLinkerProcessor, IPreprocessBuildWithReport, IPostprocessBuildWithReport.
| callbackOrder | Returns the relative callback order for callbacks. Callbacks with lower values are called before ones with higher values. |
| PrepareForBuild | Implement this function to receive a callback before a player build starts. |