Another attempt to fix o.o.transport.netty4.OpenSearchLoggingHandlerIT fails w/ stack overflow

modules/transport-netty4/src/internalClusterTest/java/org/opensearch/transport/netty4/OpenSearchLoggingHandlerIT.java

@@ -53,6 +53,7 @@ public class OpenSearchLoggingHandlerIT extends OpenSearchNetty4IntegTestCase {
     public void setUp() throws Exception {
         super.setUp();
         appender = MockLogAppender.createForLoggers(
+            "^[^\n]+$", /* Only consider single line log statements */
             LogManager.getLogger(OpenSearchLoggingHandler.class),
             LogManager.getLogger(TransportLogger.class),
             LogManager.getLogger(TcpTransport.class)

test/framework/src/main/java/org/opensearch/test/MockLogAppender.java

@@ -68,8 +68,12 @@ public class MockLogAppender extends AbstractAppender implements AutoCloseable {
      * write to a closed MockLogAppender instance.
      */
     public static MockLogAppender createForLoggers(Logger... loggers) throws IllegalAccessException {
+        return createForLoggers(".*(\n.*)*", loggers);
+    }
+
+    public static MockLogAppender createForLoggers(String filter, Logger... loggers) throws IllegalAccessException {
         final MockLogAppender appender = new MockLogAppender(
-            RegexFilter.createFilter(".*(\n.*)*", new String[0], false, null, null),
+            RegexFilter.createFilter(filter, new String[0], false, null, null),
             Collections.unmodifiableList(Arrays.asList(loggers))
         );
         appender.start();