Actor and former US politician Arnold Schwarzenegger was briefly detained by German customs officers at Munich Airport on Wednesday for allegedly failing to declare a valuable luxury watch. Austrian-born Schwarzenegger was eventually able to continue on his journey, said a spokesman for the main customs office in Munich on Wednesday evening. He was also able to take the watch with him. Criminal tax proceedings had been initiated against Schwarzenegger, a world-champion bodybuilder and action film star who also served two terms as governor of the US state of California. According to the customs…