Merge branch 'mrincon-remove-unused-props-store' into 'master'

Remove unused store properties

See merge request gitlab-org/gitlab!20273

app/assets/javascripts/monitoring/stores/state.js

 import invalidUrl from '~/lib/utils/invalid_url';
 
 export default () => ({
-  hasMetrics: false,
-  showPanels: true,
   metricsEndpoint: null,
   environmentsEndpoint: null,
   deploymentsEndpoint: null,