ekf2: improve flow for terrain unit test

src/modules/ekf2/test/test_EKF_terrain_estimator.cpp

@@ -73,6 +73,8 @@ public:
 		_ekf_wrapper.enableGpsFusion();
 		_ekf_wrapper.setBaroHeight();
 		_sensor_simulator.runSeconds(2); // Run to pass the GPS checks
+		_sensor_simulator.runSeconds(3.2); // And a bit more to start the GPS fusion TODO: this shouldn't be necessary
+		EXPECT_TRUE(_ekf_wrapper.isIntendingGpsFusion());
 
 		const Vector3f simulated_velocity(0.5f, -1.0f, 0.f);
 
@@ -98,7 +100,7 @@ public:
 		_sensor_simulator.startFlow();
 
 		_ekf->set_in_air_status(true);
-		_sensor_simulator.runSeconds(8);
+		_sensor_simulator.runSeconds(7);
 	}
 };