Ensure warm up engine in testTranslogReplayWithFailure

We need to warm up the engine (i.e., perform an external refresh) before
accessing the external refresh. Note that we refresh externally before
allowing reading from a shard.

Relates #48605
Closes #51548

server/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java

@@ -2956,6 +2956,7 @@ public class InternalEngineTests extends EngineTestCase {
                 directory.setFailOnOpenInput(false);
                 directory.setAllowRandomFileNotFoundException(false);
                 if (started) {
+                    engine.refresh("warm_up");
                     assertVisibleCount(engine, numDocs, false);
                     engine.close();
                 }