
The Objective-C `flutter create --ios-language objc` template will be removed in https://github.com/flutter/flutter/issues/148586. Add a deprecation warning when this flag is passed. Add an additional warning when Objective-C is specified requesting the user's use-case. Do not show the warning when creating the module, as Swift is not supported for it yet https://github.com/flutter/flutter/issues/23955  Part of https://github.com/flutter/flutter/issues/148586