Fix testTaskDescriptionExcludesSensitiveFields (elastic#144916)

There was a bug in the test that threw an index_not_found_exception. The
test indexed into task_api_src but the reindex source was remote_src, so
the remote reindex hit a missing index and failed. It’s fixed by
indexing into remote_src, same as
testGetReindexDescriptionStripsRemoteInfoSensitiveFields

Author: joshua-adams-1

modules/reindex-management/src/javaRestTest/java/org/elasticsearch/reindex/management/ReindexRemoteIT.java

@@ -101,7 +101,7 @@ public void testGetReindexDescriptionStripsRemoteInfoSensitiveFields() throws Ex
     }
 
     public void testTaskDescriptionExcludesSensitiveFields() throws Exception {
-        Request indexRequest = new Request("POST", "/task_api_src/_doc");
+        Request indexRequest = new Request("POST", "/remote_src/_doc");
         indexRequest.addParameter("refresh", "true");
         indexRequest.setJsonEntity("{\"field\": \"value\"}");
         client().performRequest(indexRequest);