Set Swift version and flags for DKImagePickerController in Podfile post-install

refilc/ios/Podfile

@@ -41,6 +41,10 @@ post_install do |installer|
     flutter_additional_ios_build_settings(target)
     target.build_configurations.each do |config|
       config.build_settings.delete 'IPHONEOS_DEPLOYMENT_TARGET'
+      if target.name == 'DKImagePickerController'
+        config.build_settings['SWIFT_VERSION'] = '5.0'
+        config.build_settings['OTHER_SWIFT_FLAGS'] = '$(inherited) -Xfrontend -disable-reflection-metadata'
+      end
     end
   end