[8.x] Add CCS tests for logsdb (#113658) (#113691)

* Add CCS tests for logsdb (#113658)

Closes #109805

* compile

Author: dnhatn

modules/data-streams/src/javaRestTest/java/org/elasticsearch/datastreams/LogsDataStreamRestIT.java

@@ -73,7 +73,7 @@ private static void waitForLogs(RestClient client) throws Exception {
         });
     }
 
-    private static final String LOGS_TEMPLATE = """
+    static final String LOGS_TEMPLATE = """
         {
           "index_patterns": [ "logs-*-*" ],
           "data_stream": {},
@@ -110,7 +110,7 @@ private static void waitForLogs(RestClient client) throws Exception {
           }
         }""";
 
-    private static final String LOGS_STANDARD_INDEX_MODE = """
+    static final String LOGS_STANDARD_INDEX_MODE = """
         {
           "index_patterns": [ "logs-*-*" ],
           "data_stream": {},
@@ -143,7 +143,7 @@ private static void waitForLogs(RestClient client) throws Exception {
           }
         }""";
 
-    private static final String STANDARD_TEMPLATE = """
+    static final String STANDARD_TEMPLATE = """
         {
           "index_patterns": [ "standard-*-*" ],
           "data_stream": {},
@@ -216,7 +216,7 @@ private static void waitForLogs(RestClient client) throws Exception {
           }
         }""";
 
-    private static final String DOC_TEMPLATE = """
+    static final String DOC_TEMPLATE = """
         {
             "@timestamp": "%s",
             "host.name": "%s",
@@ -588,7 +588,7 @@ private void assertDataStreamBackingIndexMode(final String indexMode, int backin
         assertThat(getSettings(client, getWriteBackingIndex(client, dataStreamName, backingIndex)).get("index.mode"), is(indexMode));
     }
 
-    private String document(
+    static String document(
         final Instant timestamp,
         final String hostname,
         long pid,
@@ -615,13 +615,13 @@ private static void createDataStream(final RestClient client, final String dataS
         assertOK(client.performRequest(request));
     }
 
-    private static void putTemplate(final RestClient client, final String templateName, final String mappings) throws IOException {
+    static void putTemplate(final RestClient client, final String templateName, final String mappings) throws IOException {
         final Request request = new Request("PUT", "/_index_template/" + templateName);
         request.setJsonEntity(mappings);
         assertOK(client.performRequest(request));
     }
 
-    private static void indexDocument(final RestClient client, String indexOrtDataStream, String doc) throws IOException {
+    static void indexDocument(final RestClient client, String indexOrtDataStream, String doc) throws IOException {
         final Request request = new Request("POST", "/" + indexOrtDataStream + "/_doc?refresh=true");
         request.setJsonEntity(doc);
         final Response response = client.performRequest(request);