use sentence casing in binary_sensor for fressnapf_tracker (home-assistant#157772)

Author: eifinger

homeassistant/components/fressnapf_tracker/strings.json

@@ -49,7 +49,7 @@
   "entity": {
     "binary_sensor": {
       "deep_sleep": {
-        "name": "Deep Sleep"
+        "name": "Deep sleep"
       }
     }
   }

tests/components/fressnapf_tracker/snapshots/test_binary_sensor.ambr

@@ -73,7 +73,7 @@
     }),
     'original_device_class': <BinarySensorDeviceClass.POWER: 'power'>,
     'original_icon': None,
-    'original_name': 'Deep Sleep',
+    'original_name': 'Deep sleep',
     'platform': 'fressnapf_tracker',
     'previous_unique_id': None,
     'suggested_object_id': None,
@@ -87,7 +87,7 @@
   StateSnapshot({
     'attributes': ReadOnlyDict({
       'device_class': 'power',
-      'friendly_name': 'Fluffy Deep Sleep',
+      'friendly_name': 'Fluffy Deep sleep',
     }),
     'context': <ANY>,
     'entity_id': 'binary_sensor.fluffy_deep_sleep',