Onboarded opensearch apis to use MDS client for Neo (#1313)

Signed-off-by: Amardeepsingh Siglani <[email protected]>

cr: https://code.amazon.com/reviews/CR-234395069

Author: amsiglan

server/routes/opensearch.js

@@ -62,23 +62,29 @@ export default function (services, router, dataSourceEnabled) {
   router.get(
     {
       path: '/api/alerting/_plugins',
-      validate: false,
+      validate: {
+        query: createValidateQuerySchema(dataSourceEnabled),
+      },
     },
     opensearchService.getPlugins
   );
 
   router.get(
     {
       path: '/api/alerting/_settings',
-      validate: false,
+      validate: {
+        query: createValidateQuerySchema(dataSourceEnabled),
+      },
     },
     opensearchService.getSettings
   );
 
   router.get(
     {
       path: '/api/alerting/_health',
-      validate: false,
+      validate: {
+        query: createValidateQuerySchema(dataSourceEnabled),
+      },
     },
     opensearchService.getClusterHealth
   );