Folding one's hands after ruku when praying behind a imaam who reads longer zikr than ''Rabbana lakal hamd''

Q: Must a Hanafi fold his hands after ruku when he prays behind a imaam who does longer zikr than ''Rabbana lakal hamd'' such as;

رَبَّنا وَلَكَ الحَمْدُ حَمْداً كَثيراً طَيِّباً مُبارَكاً فيه

Rabbana wa laka l-h'amd, h'amdan kathiran tayyiban mubaarakan fih