Fix flaky feature spec

For some reason we need to create clusters_applications_prometheus
before stubbing Kube client discover request

ee/spec/features/clusters/cluster_health_dashboard_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Cluster Health board', :js, :use_clean_rails_memory_store_caching, :sidekiq_inline do
+  include KubernetesHelpers
+  include PrometheusHelpers
+
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:clusterable) { create(:project) }
+  let_it_be(:cluster) { create(:cluster, :provided_by_gcp, :project, projects: [clusterable]) }
+  let_it_be(:cluster_path) { project_cluster_path(clusterable, cluster) }
+
+  before do
+    stub_licensed_features(cluster_health: true)
+
+    clusterable.add_maintainer(current_user)
+
+    sign_in(current_user)
+  end
+
+  it 'shows cluster board section within the page' do
+    visit cluster_path
+
+    expect(page).to have_text('Cluster health')
+    expect(page).to have_css('#cluster-health')
+  end
+
+  context 'no prometheus installed' do
+    it 'shows install prometheus message' do
+      visit cluster_path
+
+      expect(page).to have_text('you must first install Prometheus below')
+    end
+  end
+
+  context 'when there is cluster with installed prometheus' do
+    before do
+      create(:clusters_applications_prometheus, :installed, cluster: cluster)
+      stub_kubeclient_discover(cluster.platform.api_url)
+    end
+
+    context 'waiting for data' do
+      before do
+        stub_empty_response
+      end
+
+      it 'shows container and waiting for data message' do
+        visit cluster_path
+        wait_for_requests
+
+        expect(page).to have_css('.prometheus-graphs')
+        expect(page).to have_text('Waiting for performance data')
+      end
+    end
+
+    context 'connected, prometheus returns data' do
+      before do
+        stub_connected
+      end
+
+      it 'renders charts' do
+        visit cluster_path
+        wait_for_requests
+
+        expect(page).to have_css('.prometheus-graphs')
+        expect(page).to have_css('.prometheus-graph')
+        expect(page).to have_css('.prometheus-graph-title')
+        expect(page).to have_css('[_echarts_instance_]')
+        expect(page).to have_css('.gl-legend')
+      end
+    end
+
+    def stub_empty_response
+      stub_prometheus_request(/prometheus-prometheus-server/, status: 204, body: {})
+      stub_prometheus_request(/prometheus\/api\/v1/, status: 204, body: {})
+    end
+
+    def stub_connected
+      stub_prometheus_request(/prometheus-prometheus-server/, body: prometheus_values_body)
+      stub_prometheus_request(/prometheus\/api\/v1/, body: prometheus_values_body)
+    end
+  end
+end