By Uditha Jayasinghe and Alasdair Pal COLOMBO (Reuters) -Sri Lankan President Gotabaya Rajapaksa declared a state of emergency on Friday following a day of anti-government strikes and protests over a worsening economic crisis. The measure, which drew immediate criticism from opposition leader Sajith Premadasa and from Canada’s ambassador, is effective immediately and was taken in the interests of public security, a government notice said. Police earlier fired tear gas at dozens of demonstrators outside parliament, in the latest in more than a month of sporadically violent anti-government prote…