Implementation of the IFileSystem interface for Android platform.

You can find more information in comments below. Overrided methods can be found in corresponding base interface.

// To work with application assets instead of file system use assets: prefix in filters, names, pathes. Please note, assets are readonly, any changes will fail 
    class CFileSystem :public virtual IFileSystem
    {
    public:
        bool SearchFiles(const String &filter, SearchFilesResult &result) override; // In case of searching in assets only files could be searched. There is no way to search directories in the assets using Android NDK 
        bool FileExists(const String &filename) override;
        bool DirectoryExists(const String &path) override;
        SearchDrivesResult SearchDrives() override; // Not supported. Return empty result 
        // Since 5.0.0 
        IFile *FileOpen(const String &filename, const OPEN_MODE open_mode, const bool read, const bool write,
                // Following remaining parameters are not supported
                const bool share_delete = false, const bool share_read = false, const bool share_write = false, const bool archieved = false, const bool encrypted = false,
                const bool hidden = false, const bool offline = false, const bool readonly = false, const bool system = false, const bool temporary = false, const bool delete_on_close = false,
                const bool no_buffering = false, const bool random_access = false) override;
        bool FileCopy(const String &filename, const String &new_filename,
                const bool overwrite_existing) override; // This parameter is not supported 
        bool FileMove(const String &filename, const String &new_filename,
                const bool overwrite_existing) override; // This parameter is not supported 
        bool FileDelete(const String &filename) override;
        bool DirectoryCreate(const String &path) override;
        bool DirectoryMove(const String &path, const String &new_path, const bool overwrite_existing) override;
        bool DirectoryDelete(const String &path) override;
    
        CFileSystem(CApplication *application);
    };