Move temperature conversions to sensor base class (4/8) (#54472)

* Move temperature conversions to entity base class (4/8)

* Fix litterrobot sensor

* Fix tests

homeassistant/components/keba/sensor.py

@@ -104,12 +104,12 @@ class KebaSensor(SensorEntity):
         return self._icon
 
     @property
-    def state(self):
+    def native_value(self):
         """Return the state of the sensor."""
         return self._state
 
     @property
-    def unit_of_measurement(self):
+    def native_unit_of_measurement(self):
         """Get the unit of measurement."""
         return self._unit