AP_NavEKF3: Re-tune tilt alignment check

New tilt error variance estimate is more accurate and larger than before.

libraries/AP_NavEKF3/AP_NavEKF3_Control.cpp

@@ -411,7 +411,7 @@ void NavEKF3_core::checkAttitudeAlignmentStatus()
     // Once the tilt variances have reduced to equivalent of 3deg uncertainty, re-set the yaw and magnetic field states
     // and declare the tilt alignment complete
     if (!tiltAlignComplete) {
-        if (tiltErrorVariance < sq(radians(3.0f))) {
+        if (tiltErrorVariance < sq(radians(5.0f))) {
             tiltAlignComplete = true;
             gcs().send_text(MAV_SEVERITY_INFO, "EKF3 IMU%u tilt alignment complete",(unsigned)imu_index);
         }