Fix utility meter restore state (#66490)

* Address #63874

* avoid setting _last_period to None

* name is always set in discovery

* ValueError never happens only DecimalException

* async_tariff_change tracks state change - state machine will not pass a None

* test we only reset one utility_meter

* test corrupted restored state

* pretty sure _current_tariff doesn't change from init until here

* missing assert

* Revert "async_tariff_change tracks state change - state machine will not pass a None"

This reverts commit 24fc04a964.

* address review comment

* always a Decimal

tests/components/utility_meter/test_init.py

@@ -62,7 +62,12 @@ async def test_services(hass):
                 "source": "sensor.energy",
                 "cycle": "hourly",
                 "tariffs": ["peak", "offpeak"],
-            }
+            },
+            "energy_bill2": {
+                "source": "sensor.energy",
+                "cycle": "hourly",
+                "tariffs": ["peak", "offpeak"],
+            },
         }
     }
 
@@ -153,6 +158,10 @@ async def test_services(hass):
     state = hass.states.get("sensor.energy_bill_offpeak")
     assert state.state == "0"
 
+    # meanwhile energy_bill2_peak accumulated all kWh
+    state = hass.states.get("sensor.energy_bill2_peak")
+    assert state.state == "4"
+
 
 async def test_cron(hass, legacy_patchable_time):
     """Test cron pattern and offset fails."""