Deprecate any uses of class_name with Class objects

Rails 5.1 dropped support for query values of type Class, and we should
have fixed most of them with ManageIQ#18827 and ManageIQ#18829, but since detecting
callers to put_or_update that do this could be difficult, we can still
support this by "fixing" it so rails 5.1 doesn't raise an exception,
and give us time to fix the caller.

app/models/miq_queue.rb

@@ -565,11 +565,17 @@ def activate_miq_task(args)
 
  # default values for get operations
  def self.default_get_options(options)
- options.reverse_merge(
+ result = options.reverse_merge(
  :queue_name => DEFAULT_QUEUE,
  :state => STATE_READY,
  :zone => Zone.determine_queue_zone(options)
  )
+
+ if result[:class_name].kind_of?(Class)
+ ActiveSupport::Deprecation.warn("Rails 5.1 dropped support for Class query values, use a String for class_name.", caller[1..-1])
+ result[:class_name] = result[:class_name].name
+ end
+ result
  end
 
  private_class_method :default_get_options

spec/models/miq_queue_spec.rb

@@ -718,6 +718,16 @@ def self.some_method(single_arg)
  expect(MiqQueue.first.args).to eq([3, 3])
  end
 
+ it "supports a Class object for the class name(deprecated)" do
+ expect(ActiveSupport::Deprecation).to receive(:warn).with(/use a String for class_name/, anything)
+ msg = MiqQueue.put_or_update(:class_name => MiqServer, :instance_id => @miq_server.id, :method_name => "my_zone")
+
+ status, message, result = msg.deliver
+ expect(status).to eq(MiqQueue::STATUS_OK)
+ expect(message).to eq("Message delivered successfully")
+ expect(result).to eq(@miq_server.my_zone)
+ end
+
  it "should use args param to find messages on the queue" do
  MiqQueue.put(
  :class_name => 'MyClass',