ekf2: reduce GPS initialization time for SITL from 10s to 0.5s

Speeds up SITL startup.

src/modules/ekf2/ekf2_params.c

@@ -1355,3 +1355,17 @@ PARAM_DEFINE_FLOAT(EKF2_GPS_TAU, 10.0f);
  * @decimal 1
  */
 PARAM_DEFINE_FLOAT(EKF2_MOVE_TEST, 1.0f);
+
+/**
+ * Required GPS health time on startup
+ *
+ * Minimum continuous period without GPS failure required to mark a healthy GPS status.
+ * It can be reduced to speed up initialization, but it's recommended to keep this unchanged for a vehicle.
+ *
+ * @group EKF2
+ * @min 0.1
+ * @decimal 1
+ * @unit s
+ * @reboot_required true
+ */
+PARAM_DEFINE_FLOAT(EKF2_REQ_GPS_H, 10.0f);