On HA restart parse last_reset as a datetime object (#42939)

homeassistant/components/utility_meter/sensor.py

@@ -264,7 +264,9 @@ class UtilityMeterSensor(RestoreEntity):
             self._state = Decimal(state.state)
             self._unit_of_measurement = state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
             self._last_period = state.attributes.get(ATTR_LAST_PERIOD)
-            self._last_reset = state.attributes.get(ATTR_LAST_RESET)
+            self._last_reset = dt_util.parse_datetime(
+                state.attributes.get(ATTR_LAST_RESET)
+            )
             self.async_write_ha_state()
             if state.attributes.get(ATTR_STATUS) == PAUSED:
                 # Fake cancellation function to init the meter paused