Don't start the push updater if the Apple TV is 'off' (#6552)

Add an optional extended description…

homeassistant/components/media_player/apple_tv.py

@@ -96,6 +96,7 @@ class AppleTvDevice(MediaPlayerDevice):
     @asyncio.coroutine
     def async_added_to_hass(self):
         """Called when entity is about to be added to HASS."""
+        if not self._is_off:
             self._atv.push_updater.start()
 
     @callback