Set brand icon as entity picture on update entities (#69200)

Co-authored-by: Joakim Sørensen <ludeeus@ludeeus.dev>

homeassistant/components/update/__init__.py

@@ -208,6 +208,20 @@ class UpdateEntity(RestoreEntity):
             return EntityCategory.CONFIG
         return EntityCategory.DIAGNOSTIC
 
+    @property
+    def entity_picture(self) -> str | None:
+        """Return the entity picture to use in the frontend.
+
+        Update entities return the brand icon based on the integration
+        domain by default.
+        """
+        if self.platform is None:
+            return None
+
+        return (
+            f"https://brands.home-assistant.io/_/{self.platform.platform_name}/icon.png"
+        )
+
     @property
     def in_progress(self) -> bool | int | None:
         """Update installation progress.