v3(tests): add tests for service key last operation in response

[#174252663](https://www.pivotaltracker.com/story/show/174252663)

Author: pivotal-marcela-campo

spec/request/service_credential_bindings_spec.rb

@@ -434,7 +434,11 @@ def check_filtered_bindings(*bindings)
     end
 
     describe 'key credential binding' do
-      let(:key) { VCAP::CloudController::ServiceKey.make(service_instance: instance) }
+      let(:key) do
+        VCAP::CloudController::ServiceKey.make(service_instance: instance) do |binding|
+          operate_on(binding)
+        end
+      end
       let(:instance) { VCAP::CloudController::ManagedServiceInstance.make(space: space) }
       let(:api_call) { ->(user_headers) { get "/v3/service_credential_bindings/#{key.guid}", nil, user_headers } }
       let(:expected_object) { expected_json(key) }
@@ -782,7 +786,7 @@ def check_filtered_bindings(*bindings)
 
         context 'when an operation is still on going for the binding' do
           before do
-            binding.save_with_new_operation({ type: 'create', state: 'in progress' })
+            binding.save_with_attributes_and_new_operation({}, { type: 'create', state: 'in progress' })
           end
 
           it 'should fail as not allowed' do
@@ -1933,7 +1937,8 @@ def last_operation(binding)
   end
 
   def operate_on(binding)
-    binding.save_with_new_operation(
+    binding.save_with_attributes_and_new_operation(
+      {},
       {
         type: 'create',
         state: 'succeeded',

spec/unit/presenters/v3/service_credential_binding_presenter_spec.rb

@@ -10,7 +10,8 @@ module CloudController
       describe 'app bindings' do
         let(:credential_binding) do
           ServiceBinding.make(name: 'some-name', guid: 'some-guid', app: app, service_instance: instance).tap do |binding|
-            binding.save_with_new_operation(
+            binding.save_with_attributes_and_new_operation(
+              {},
               {
                 type: 'create',
                 state: 'succeeded',
@@ -101,12 +102,21 @@ module CloudController
 
       describe 'key bindings' do
         let(:credential_binding) do
-          ServiceKey.make(name: 'some-name', guid: 'some-guid', service_instance: instance)
+          ServiceKey.make(name: 'some-name', guid: 'some-guid', service_instance: instance).tap do |binding|
+            binding.save_with_attributes_and_new_operation(
+              {},
+              {
+                type: 'create',
+                state: 'succeeded',
+                description: 'some description'
+              }
+            )
+          end
         end
 
         it 'should include the binding fields plus links and relationships' do
           presenter = described_class.new(credential_binding)
-          expect(presenter.to_hash).to match(
+          expect(presenter.to_hash.with_indifferent_access).to match(
             {
               guid: 'some-guid',
               type: 'key',
@@ -116,7 +126,7 @@ module CloudController
               last_operation: {
                 type: 'create',
                 state: 'succeeded',
-                description: '',
+                description: 'some description',
                 updated_at: credential_binding.updated_at,
                 created_at: credential_binding.created_at
               },