Add DartDoc for UiKitViewController#acceptGesture (#24127)

packages/flutter/lib/src/services/platform_views.dart

@@ -617,6 +617,11 @@ class UiKitViewController {
     // TODO(amirh): invoke the iOS platform views channel direction method once available.
   }
 
+  /// Accept an active gesture.
+  ///
+  /// When a touch sequence is happening on the embedded UIView all touch events are delayed.
+  /// Calling this method releases the delayed events to the embedded UIView and makes it consume
+  /// any following touch events for the pointers involved in the active gesture.
   Future<void> acceptGesture() {
     final Map<String, dynamic> args = <String, dynamic> {
       'id': id,