AP_NavEKF2: Fix reporting of terrain estimator innovations

Terrain height is relevant whenever optical flow data is present

libraries/AP_NavEKF2/AP_NavEKF2_Outputs.cpp

@@ -520,10 +520,11 @@ void NavEKF2_core::send_status_report(mavlink_channel_t chan)
     Vector2f offset;
     getVariances(velVar, posVar, hgtVar, magVar, tasVar, offset);
 
-    // Only report range finder normalised innovation levels if the EKF needs the data.
-    // This prevents false alarms at the GCS if a range finder is fitted for other applications
+    // Only report range finder normalised innovation levels if the EKF needs the data for primary
+    // height estimation or optical flow operation. This prevents false alarms at the GCS if a
+    // range finder is fitted for other applications
     float temp;
-    if ((frontend->_useRngSwHgt > 0) || PV_AidingMode == AID_RELATIVE) {
+    if ((frontend->_useRngSwHgt > 0) || PV_AidingMode == AID_RELATIVE || flowDataValid) {
         temp = sqrtf(auxRngTestRatio);
     } else {
         temp = 0.0f;