mavlink: use 4s for HITL

This is more inline with SITL.

src/modules/mavlink/mavlink_receiver.cpp

@@ -2215,10 +2215,12 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		battery_status_s hil_battery_status{};
 
 		hil_battery_status.timestamp = timestamp;
-		hil_battery_status.voltage_v = 11.5f;
-		hil_battery_status.voltage_filtered_v = 11.5f;
+		hil_battery_status.voltage_v = 16.0f;
+		hil_battery_status.voltage_filtered_v = 16.0f;
 		hil_battery_status.current_a = 10.0f;
 		hil_battery_status.discharged_mah = -1.0f;
+		hil_battery_status.connected = true;
+		hil_battery_status.remaining = 0.70;
 
 		_battery_pub.publish(hil_battery_status);
 	}