Improve spec performance for feature flag services

Refactor to use let_it_be

spec/services/feature_flags/create_service_spec.rb

@@ -3,12 +3,12 @@
 require 'spec_helper'
 
 RSpec.describe FeatureFlags::CreateService do
-  let(:project) { create(:project) }
-  let(:developer) { create(:user) }
-  let(:reporter) { create(:user) }
+  let_it_be(:project) { create(:project) }
+  let_it_be(:developer) { create(:user) }
+  let_it_be(:reporter) { create(:user) }
   let(:user) { developer }
 
-  before do
+  before_all do
     project.add_developer(developer)
     project.add_reporter(reporter)
   end

spec/services/feature_flags/destroy_service_spec.rb

@@ -5,13 +5,13 @@ require 'spec_helper'
 RSpec.describe FeatureFlags::DestroyService do
   include FeatureFlagHelpers
 
-  let(:project) { create(:project) }
-  let(:developer) { create(:user) }
-  let(:reporter) { create(:user) }
+  let_it_be(:project) { create(:project) }
+  let_it_be(:developer) { create(:user) }
+  let_it_be(:reporter) { create(:user) }
   let(:user) { developer }
   let!(:feature_flag) { create(:operations_feature_flag, project: project) }
 
-  before do
+  before_all do
     project.add_developer(developer)
     project.add_reporter(reporter)
   end

spec/services/feature_flags/disable_service_spec.rb

@@ -5,12 +5,12 @@ require 'spec_helper'
 RSpec.describe FeatureFlags::DisableService do
   include FeatureFlagHelpers
 
+  let_it_be(:project) { create(:project) }
   let_it_be(:user) { create(:user) }
-  let(:project) { create(:project) }
-  let(:service) { described_class.new(project, user, params) }
   let(:params) { {} }
+  let(:service) { described_class.new(project, user, params) }
 
-  before do
+  before_all do
     project.add_developer(user)
   end
 

spec/services/feature_flags/enable_service_spec.rb

@@ -5,12 +5,12 @@ require 'spec_helper'
 RSpec.describe FeatureFlags::EnableService do
   include FeatureFlagHelpers
 
+  let_it_be(:project) { create(:project) }
   let_it_be(:user) { create(:user) }
-  let(:project) { create(:project) }
-  let(:service) { described_class.new(project, user, params) }
   let(:params) { {} }
+  let(:service) { described_class.new(project, user, params) }
 
-  before do
+  before_all do
     project.add_developer(user)
   end
 

spec/services/feature_flags/update_service_spec.rb

@@ -3,13 +3,13 @@
 require 'spec_helper'
 
 RSpec.describe FeatureFlags::UpdateService do
-  let(:project) { create(:project) }
-  let(:developer) { create(:user) }
-  let(:reporter) { create(:user) }
+  let_it_be(:project) { create(:project) }
+  let_it_be(:developer) { create(:user) }
+  let_it_be(:reporter) { create(:user) }
   let(:user) { developer }
   let(:feature_flag) { create(:operations_feature_flag, project: project, active: true) }
 
-  before do
+  before_all do
     project.add_developer(developer)
     project.add_reporter(reporter)
   end