Use internal connection manager when fetching remote node info

This reverts commit 4975b57.
This reverts commit ca2c228.

Closes #33128

Author: s1monw

qa/multi-cluster-search/src/test/resources/rest-api-spec/test/multi_cluster/20_info.yml

@@ -1,8 +1,6 @@
 ---
 "Fetch remote cluster info for existing cluster":
-  - skip:
-      version: "all"
-      reason: https://github.com/elastic/elasticsearch/issues/33128
+
   - do:
       cluster.remote_info: {}
   - match: { my_remote_cluster.connected: true }
@@ -13,9 +11,6 @@
 
 ---
 "Add transient remote cluster based on the preset cluster and check remote info":
-  - skip:
-      version: "all"
-      reason: https://github.com/elastic/elasticsearch/issues/33128
   - do:
       cluster.get_settings:
         include_defaults: true
@@ -70,11 +65,8 @@
 ---
 "skip_unavailable is returned as part of _remote/info response":
   - skip:
-      version: "all"
-      reason: https://github.com/elastic/elasticsearch/issues/33128
-  #- skip:
-  #    version: " - 6.0.99"
-  #    reason: "skip_unavailable is only returned from 6.1.0 on"
+      version: " - 6.0.99"
+      reason: "skip_unavailable is only returned from 6.1.0 on"
 
   - do:
       cluster.get_settings:

server/src/main/java/org/elasticsearch/transport/RemoteClusterConnection.java

@@ -686,8 +686,9 @@ public void getConnectionInfo(ActionListener<RemoteConnectionInfo> listener) {
             NodesInfoRequest request = new NodesInfoRequest();
             request.clear();
             request.http(true);
-
-            transportService.sendRequest(anyNode.get(), NodesInfoAction.NAME, request, new TransportResponseHandler<NodesInfoResponse>() {
+            Transport.Connection connection = connectionManager.getConnection(anyNode.get());
+            transportService.sendRequest(connection, NodesInfoAction.NAME, request, TransportRequestOptions.EMPTY,
+                new TransportResponseHandler<NodesInfoResponse>() {
                 @Override
                 public NodesInfoResponse newInstance() {
                     return new NodesInfoResponse();

x-pack/qa/multi-cluster-search-security/src/test/resources/rest-api-spec/test/multi_cluster/20_info.yml

@@ -33,9 +33,6 @@ teardown:
         ignore: 404
 ---
 "Fetch remote cluster info for existing cluster":
-  - skip:
-      version: "all"
-      reason: https://github.com/elastic/elasticsearch/issues/33128
 
   - do:
       headers: { Authorization: "Basic am9lOnMza3JpdA==" }
@@ -49,10 +46,6 @@ teardown:
 
 ---
 "Add transient remote cluster based on the preset cluster and check remote info":
-  - skip:
-      version: "all"
-      reason: https://github.com/elastic/elasticsearch/issues/33128
-
   - do:
       cluster.get_settings:
         include_defaults: true
@@ -94,3 +87,4 @@ teardown:
 
   - match: { my_remote_cluster.initial_connect_timeout: "30s" }
   - match: { test_remote_cluster.initial_connect_timeout: "30s" }
+