By Devjyot Ghoshal and Uditha Jayasinghe COLOMBO (Reuters) -In June, a few dozen activists started meeting regularly at a seaside tented camp in Colombo for hours-long sessions to think up ways to revive Sri Lanka’s flagging protest movement. The group, which included a Catholic priest, a digital strategist and a popular playwright, succeeded beyond their wildest hopes. Within weeks, hundreds of thousands of people descended on Colombo. After initially clashing with police, protesters occupied key government buildings and residences, forcing President Gotabaya Rajapaksa and his prime minister …