[Windows]: When using the EnvironmentVariable operation it can change the registry value type from REG_EXPAND_SZ to REG_SZ

If registery value type is REG_EXPAND_SZ when write value, it will be force changed to REG_SZ because QSettings does not have support for REG_EXPAND_SZ in

void QWinSettingsPrivate::set(const QString &uKey, const QVariant &value) in

src/corelib/io/qsettings_win.cpp.