Complete TODO for cameras on robots 'is_connected'

lerobot/common/robots/lekiwi/lekiwi.py

@@ -102,8 +102,7 @@ class LeKiwi(Robot):
 
     @property
     def is_connected(self) -> bool:
-        # TODO(aliberts): add cam.is_connected for cam in self.cameras
-        return self.bus.is_connected
+        return self.bus.is_connected and all(cam.is_connected for cam in self.cameras.values())
 
     def connect(self, calibrate: bool = True) -> None:
         if self.is_connected: