In a strange incident, Gov. Phil Murphy’s latest coronavirus briefing was abruptly cut short Wednesday when a fire alarm started blaring inside the Trenton War Memorial and everyone in the room was evacuated. The alarm began as a reporter was in the middle of asking Murphy questions about the effectiveness of his previous COVID-19 lockdown orders and the metrics he’ll use to determine whether to extend the new public-health emergency. The governor and others in the room started looking around with confusion. “I did it deliberately,” Murphy said with a smile as the alarm blared. The live feed o…