Fix: remove unnecessary trailing slash from REST paths. (#11992) (#11995)

(cherry picked from commit 4167ac5)

Signed-off-by: dblock <dblock@amazon.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: opensearch-trigger-bot[bot]

server/src/main/java/org/opensearch/rest/action/admin/cluster/RestRemoteClusterInfoAction.java

@@ -53,7 +53,7 @@ public final class RestRemoteClusterInfoAction extends BaseRestHandler {
 
     @Override
     public List<Route> routes() {
-        return singletonList(new Route(GET, "_remote/info"));
+        return singletonList(new Route(GET, "/_remote/info"));
     }
 
     @Override

server/src/main/java/org/opensearch/rest/action/admin/indices/RestPutMappingAction.java

@@ -66,10 +66,10 @@ public class RestPutMappingAction extends BaseRestHandler {
     public List<Route> routes() {
         return unmodifiableList(
             asList(
-                new Route(POST, "/{index}/_mapping/"),
-                new Route(PUT, "/{index}/_mapping/"),
-                new Route(POST, "/{index}/_mappings/"),
-                new Route(PUT, "/{index}/_mappings/")
+                new Route(POST, "/{index}/_mapping"),
+                new Route(PUT, "/{index}/_mapping"),
+                new Route(POST, "/{index}/_mappings"),
+                new Route(PUT, "/{index}/_mappings")
             )
         );
     }