[Controls] Add Expensive Queries Fallback (#155082)

## Summary
If the user has no permission to check for the value of `allow_expensive_queries`, it will now default to true instead of false.

src/plugins/controls/server/options_list/options_list_cluster_settings_route.ts

@@ -8,6 +8,7 @@
 
 import { getKbnServerError, reportServerError } from '@kbn/kibana-utils-plugin/server';
 import { CoreSetup } from '@kbn/core/server';
+import { errors } from '@elastic/elasticsearch';
 
 export const setupOptionsListClusterSettingsRoute = ({ http }: CoreSetup) => {
   const router = http.createRouter();
@@ -39,6 +40,17 @@ export const setupOptionsListClusterSettingsRoute = ({ http }: CoreSetup) => {
           },
         });
       } catch (e) {
+        if (e instanceof errors.ResponseError && e.body.error.type === 'security_exception') {
+          /**
+           * in cases where the user does not have the 'monitor' permission this check will fail. In these cases, we will
+           * fall back to assume that the allowExpensiveQueries setting is on, because it defaults to true.
+           */
+          return response.ok({
+            body: {
+              allowExpensiveQueries: true,
+            },
+          });
+        }
         const kbnErr = getKbnServerError(e);
         return reportServerError(response, kbnErr);
       }