Handle capitalized HomeKit property names (#21382)

The Velux ACTIVE gateway uses `C#` rather than `c#` as the name of
the property that holds the count of accessories. Apple's HomeKit docs
suggest that properties should be case-insensitive, so update the
code to not assume the property names are lower case.

tests/components/homekit_controller/common.py

@@ -134,8 +134,11 @@ class FakeService(AbstractService):
         return char
 
 
-async def setup_test_component(hass, services):
-    """Load a fake homekit accessory based on a homekit accessory model."""
+async def setup_test_component(hass, services, capitalize=False):
+    """Load a fake homekit accessory based on a homekit accessory model.
+
+    If capitalize is True, property names will be in upper case.
+    """
     domain = None
     for service in services:
         service_name = ServicesTypes.get_short(service.type)
@@ -162,9 +165,9 @@ async def setup_test_component(hass, services):
         'host': '127.0.0.1',
         'port': 8080,
         'properties': {
-            'md': 'TestDevice',
-            'id': '00:00:00:00:00:00',
-            'c#': 1,
+            ('MD' if capitalize else 'md'): 'TestDevice',
+            ('ID' if capitalize else 'id'): '00:00:00:00:00:00',
+            ('C#' if capitalize else 'c#'): 1,
         }
     }