Nav: Reset backoff on route clearing (#29067)

* nav backoff reset

* need to reset countdown as well

---------

Co-authored-by: Shane Smiskol <shane@smiskol.com>

selfdrive/navd/navd.py

@@ -102,6 +102,7 @@ class RouteEngine:
     new_destination = coordinate_from_param("NavDestination", self.params)
     if new_destination is None:
       self.clear_route()
+      self.reset_recompute_limits()
       return
 
     should_recompute = self.should_recompute()
@@ -265,8 +266,7 @@ class RouteEngine:
     if distance_to_maneuver_along_geometry < -MANEUVER_TRANSITION_THRESHOLD:
       if self.step_idx + 1 < len(self.route):
         self.step_idx += 1
-        self.recompute_backoff = 0
-        self.recompute_countdown = 0
+        self.reset_recompute_limits()
       else:
         cloudlog.warning("Destination reached")
         Params().remove("NavDestination")
@@ -293,6 +293,10 @@ class RouteEngine:
     self.step_idx = None
     self.nav_destination = None
 
+  def reset_recompute_limits(self):
+    self.recompute_backoff = 0
+    self.recompute_countdown = 0
+
   def should_recompute(self):
     if self.step_idx is None or self.route is None:
       return True