update demo service domain and service description (#29164)

* update demo service domain and service description

* move DOMAIN and service name to const.py

* update per balloob's service name suggestion

* update service name in services.yaml

* update service name constant's name

homeassistant/components/demo/const.py

@@ -0,0 +1,3 @@
+"""Constants for the Demo component."""
+DOMAIN = "demo"
+SERVICE_RANDOMIZE_DEVICE_TRACKER_DATA = "randomize_device_tracker_data"

homeassistant/components/demo/device_tracker.py

@@ -1,7 +1,7 @@
 """Demo platform for the Device tracker component."""
 import random
 
-from homeassistant.components.device_tracker import DOMAIN
+from .const import DOMAIN, SERVICE_RANDOMIZE_DEVICE_TRACKER_DATA
 
 
 def setup_scanner(hass, config, see, discovery_info=None):
@@ -36,6 +36,6 @@ def setup_scanner(hass, config, see, discovery_info=None):
         battery=53,
     )
 
-    hass.services.register(DOMAIN, "demo", observe)
+    hass.services.register(DOMAIN, SERVICE_RANDOMIZE_DEVICE_TRACKER_DATA, observe)
 
     return True

homeassistant/components/demo/services.yaml

@@ -0,0 +1,2 @@
+randomize_device_tracker_data:
+  description: Demonstrates using a device tracker to see where devices are located