A decision by the Hong Kong government to compel the city’s two biggest supermarket chains that benefited from wage subsidies to pass on gains in the form of discounts to shoppers has riled welfare groups and even pro-establishment lawmakers who attacked it as a roundabout solution.Retail and wholesale lawmaker Shiu Ka-fai on Wednesday lambasted the new requirement suddenly imposed by the government in the second tranche of the HK$81 billion wage subsidy scheme as an unnecessarily complicated…