Prediction: cleaned up gflags

modules/prediction/common/prediction_gflags.cc

@@ -63,7 +63,6 @@ DEFINE_bool(enable_pedestrian_acc, false, "Enable calculating speed by acc");
 DEFINE_double(coeff_mul_sigma, 2.0, "coefficient multiply standard deviation");
 DEFINE_double(pedestrian_min_speed, 0.1, "min speed for still pedestrian");
 DEFINE_double(pedestrian_max_speed, 10.0, "speed upper bound for pedestrian");
-DEFINE_double(pedestrian_min_acc, -4.0, "minimum pedestrian acceleration");
 DEFINE_double(pedestrian_max_acc, 2.0, "maximum pedestrian acceleration");
 DEFINE_double(prediction_pedestrian_total_time, 10.0,
               "Total prediction time for pedestrians");

modules/prediction/common/prediction_gflags.h

@@ -52,7 +52,6 @@ DECLARE_bool(enable_pedestrian_acc);
 DECLARE_double(coeff_mul_sigma);
 DECLARE_double(pedestrian_min_speed);
 DECLARE_double(pedestrian_max_speed);
-DECLARE_double(pedestrian_min_acc);
 DECLARE_double(pedestrian_max_acc);
 DECLARE_double(prediction_pedestrian_total_time);
 DECLARE_int32(num_trajectory_still_pedestrian);