India’s student-led “cockroach” protests, which began as anger over alleged entrance exam leaks, are now becoming a broader test of whether Prime Minister Narendra Modi’s government can contain young Indians’ frustration over education, jobs and accountability. The fast-growing movement gained political momentum on Tuesday when opposition leader Rahul Gandhi of the Congress party and his sister Priyanka Gandhi Vadra were forcibly removed after a gathering with about 100 fellow lawmakers outside...