Returns the state of any expansion file used by this platform, currently only applicable to Android. Returns -1 if an error occurred during download, 0 if the expansion file is not used on this platform, 1 if it should exist but doesn't (you call DownloadExpansionFile() in this case), 2 if it is currently being downloaded, and 3 if everything has completed and the file exists.
integer GetExpansionFileState()