ekf_terr: fix unit test

the flags were valid ony because they were based on timeouts and when
starting the unit test, it takes a couple of seconds to actually timeout

src/modules/ekf2/test/test_EKF_terrain_estimator.cpp

@@ -107,25 +107,20 @@ public:
 TEST_F(EkfTerrainTest, setFlowAndRangeTerrainFusion)
 {
 	// WHEN: simulate being 5m above ground
-	// By default, both rng and flow aiding are active
 	const float simulated_distance_to_ground = 1.f;
-	_sensor_simulator._rng.setData(simulated_distance_to_ground, 100);
-	_sensor_simulator._rng.setLimits(0.1f, 9.f);
-	_sensor_simulator.startRangeFinder();
-	_ekf->set_in_air_status(true);
-	_sensor_simulator.runSeconds(1.5f);
+	runFlowAndRngScenario(simulated_distance_to_ground, simulated_distance_to_ground);
 
 	// THEN: By default, both rng and flow aiding are active
 	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainRngFusion());
-	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainFlowFusion());
+	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainFlowFusion());
 	const float estimated_distance_to_ground = _ekf->getTerrainVertPos();
-	EXPECT_FLOAT_EQ(estimated_distance_to_ground, simulated_distance_to_ground);
+	EXPECT_NEAR(estimated_distance_to_ground, simulated_distance_to_ground, 1e-4);
 
 	// WHEN: rng fusion is disabled
 	_ekf_wrapper.disableTerrainRngFusion();
-	_sensor_simulator.runSeconds(0.2);
+	_sensor_simulator.runSeconds(5.);
 
-	// THEN: only rng fusion should be disabled
+	// THEN: rng fusion should be disabled and flow fusion should take over
 	EXPECT_FALSE(_ekf_wrapper.isIntendingTerrainRngFusion());
 	EXPECT_TRUE(_ekf_wrapper.isIntendingTerrainFlowFusion());