BERLIN — As Berlin reels from the energy price shock triggered by the Iran war, Russian President Vladimir Putin appears to be seizing his moment to ratchet up even more pressure on Berlin's oil supplies. Moscow is set to stop the transit of Kazakh oil to Germany via a branch of the Druzhba pipeline from May 1. That poses a major potential headache because Kazakhstan supplies almost 20 percent of the oil to the large refinery that produces 90 percent of the gasoline, jet fuel, diesel and