[flutter_tools] add more information to obfuscate option documentation (#52282)

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -400,7 +400,12 @@ abstract class FlutterCommand extends Command<void> {
         'mapping between the values and the original identifiers is stored in the '
         'symbol map created in the specified directory. For an app built with this '
         'flag, the \'flutter symbolize\' command with the right program '
-        'symbol file is required to obtain a human readable stack trace.',
+        'symbol file is required to obtain a human readable stack trace.\n\n'
+        'Because all identifiers are renamed, methods like Object.runtimeType, '
+        'Type.toString, Enum.toString, Stacktrace.toString, Symbol.toString '
+        '(for constant symbols or those generated by runtime system) will '
+        'return obfuscated results. Any code or tests that rely on exact names '
+        'will break.'
     );
   }