By Foo Yun Chee and Padraic Halpin BRUSSELS/DUBLIN, Feb 10 (Reuters) - Meta Platforms unit WhatsApp's fight against the EU privacy watchdog was sent back to ​a lower tribunal on Tuesday, prolonging a five-year tussle triggered by the ‌latter's order to the Irish data protection authority to increase a fine to 225 million euros ($268 million). The case ‌is one of many for Ireland's DPC, which is the lead privacy regulator for most of the U.S. tech giants due to the location of their EU head offices in t ...