Set default locale for cloud Alexa config (#30749)

homeassistant/components/cloud/alexa_config.py

@@ -78,6 +78,12 @@ class AlexaConfig(alexa_config.AbstractConfig):
 
         return self._endpoint
 
+    @property
+    def locale(self):
+        """Return config locale."""
+        # Not clear how to determine locale atm.
+        return "en-US"
+
     @property
     def entity_config(self):
         """Return entity config."""