Fix missing SetIdentifierFromFlutterUpdate call in ConvertFlutterUpdate

The identifier field was added to FlutterSemanticsNode2 and
SetIdentifierFromFlutterUpdate() was implemented in the 3.41.4 sync,
but the method was never called in ConvertFlutterUpdate(), causing
the identifier to be silently ignored when building the AX tree.

This is used for UI testing with tools like UI Automator, XCUITest,
and Appium that query the native accessibility hierarchy.

Author: JSUYA

flutter/shell/platform/common/accessibility_bridge.cc

@@ -292,6 +292,7 @@ void AccessibilityBridge::ConvertFlutterUpdate(const SemanticsNode& node,
   SetIntAttributesFromFlutterUpdate(node_data, node);
   SetIntListAttributesFromFlutterUpdate(node_data, node);
   SetStringListAttributesFromFlutterUpdate(node_data, node);
+  SetIdentifierFromFlutterUpdate(node_data, node);
   SetNameFromFlutterUpdate(node_data, node);
   SetValueFromFlutterUpdate(node_data, node);
   SetTooltipFromFlutterUpdate(node_data, node);