Fix race condition in samsungtv turn off (#51716)

- The state would flip flop if the update happened before the TV had fully shutdown

tests/components/samsungtv/test_media_player.py

@@ -419,6 +419,18 @@ async def test_state_without_turnon(hass, remote):
     assert await hass.services.async_call(
         DOMAIN, SERVICE_TURN_OFF, {ATTR_ENTITY_ID: ENTITY_ID_NOTURNON}, True
     )
+    state = hass.states.get(ENTITY_ID_NOTURNON)
+    # Should be STATE_UNAVAILABLE after the timer expires
+    assert state.state == STATE_OFF
+
+    next_update = dt_util.utcnow() + timedelta(seconds=20)
+    with patch(
+        "homeassistant.components.samsungtv.bridge.Remote",
+        side_effect=OSError,
+    ), patch("homeassistant.util.dt.utcnow", return_value=next_update):
+        async_fire_time_changed(hass, next_update)
+        await hass.async_block_till_done()
+
     state = hass.states.get(ENTITY_ID_NOTURNON)
     # Should be STATE_UNAVAILABLE since there is no way to turn it back on
     assert state.state == STATE_UNAVAILABLE