Specify new validation message selector

Update QA selector to specify that API URL
is a input type=url field

qa/qa/page/project/operations/kubernetes/add_existing.rb

@@ -6,7 +6,7 @@ module QA
           class AddExisting < Page::Base
             view 'app/views/clusters/clusters/user/_form.html.haml' do
               element :cluster_name, 'text_field :name' # rubocop:disable QA/ElementWithPattern
-              element :api_url, 'text_field :api_url' # rubocop:disable QA/ElementWithPattern
+              element :api_url, 'url_field :api_url' # rubocop:disable QA/ElementWithPattern
               element :ca_certificate, 'text_area :ca_cert' # rubocop:disable QA/ElementWithPattern
               element :token, 'text_field :token' # rubocop:disable QA/ElementWithPattern
               element :add_cluster_button, "submit s_('ClusterIntegration|Add Kubernetes cluster')" # rubocop:disable QA/ElementWithPattern

spec/features/groups/clusters/user_spec.rb

@@ -69,7 +69,7 @@ describe 'User Cluster', :js do
       end
 
       it 'user sees a validation error' do
-        expect(page).to have_css('#error_explanation')
+        expect(page).to have_css('.gl-field-error')
       end
     end
   end

spec/features/projects/clusters/gcp_spec.rb

@@ -92,7 +92,7 @@ describe 'Gcp Cluster', :js do
         end
 
         it 'user sees a validation error' do
-          expect(page).to have_css('#error_explanation')
+          expect(page).to have_css('.gl-field-error')
         end
       end
     end

spec/features/projects/clusters/user_spec.rb

@@ -53,7 +53,7 @@ describe 'User Cluster', :js do
       end
 
       it 'user sees a validation error' do
-        expect(page).to have_css('#error_explanation')
+        expect(page).to have_css('.gl-field-error')
       end
     end
   end