feat(avoidance): wait next shift approval until the ego reaches shift length threshold (autowarefoundation#891)

* feat(avoidance): wait next shift approval until the ego reaches shift length threshold

Signed-off-by: satoshi-ota <satoshi.ota928@gmail.com>

* fix(avoidance): param description

Signed-off-by: satoshi-ota <satoshi.ota928@gmail.com>

---------

Signed-off-by: satoshi-ota <satoshi.ota928@gmail.com>

Author: satoshi-ota

autoware_launch/config/planning/scenario_planning/lane_driving/behavior_planning/behavior_path_planner/avoidance/avoidance.param.yaml

@@ -207,6 +207,10 @@
           max_right_shift_length: 5.0
           max_left_shift_length: 5.0
           max_deviation_from_lane: 0.2                  # [m]
+          # approve the next shift line after reaching this percentage of the current shift line length.
+          # this parameter is added to allow waiting for the return of shift approval until the occlusion behind the avoid target is clear.
+          # this feature can be disabled by setting this parameter to 0.0.
+          ratio_for_return_shift_approval: 0.5          # [-]
         # avoidance distance parameters
         longitudinal:
           min_prepare_time: 1.0                         # [s]