Add check for nil auto_devops in Projects::UpdateService

app/services/projects/update_service.rb

@@ -36,7 +36,7 @@ module Projects
     end
 
     def run_auto_devops_pipeline?
-      return false if project.repository.gitlab_ci_yml || !project.auto_devops.previous_changes.include?('enabled')
+      return false if project.repository.gitlab_ci_yml || project.auto_devops.nil? || !project.auto_devops.previous_changes.include?('enabled')
 
       project.auto_devops.enabled? || (project.auto_devops.enabled.nil? && Gitlab::CurrentSettings.auto_devops_enabled?)
     end

spec/services/projects/update_service_spec.rb

@@ -275,6 +275,10 @@ describe Projects::UpdateService do
       it { is_expected.to eq(false) }
     end
 
+    context 'when auto devops is nil' do
+      it { is_expected.to eq(false) }
+    end
+
     context 'when auto devops is explicitly enabled' do
       before do
         project.create_auto_devops!(enabled: true)