Remove FailedToCommitClusterStateException from TransportClusterHealthAction (elastic#136613)

Removes a boolean check on incorrectly
thrown FailedToCommitClusterStateException's since these
were replaced with NotMasterExceptions

Relates to: ES-13061

Author: joshua-adams-1

server/src/main/java/org/elasticsearch/action/admin/cluster/health/TransportClusterHealthAction.java

@@ -24,7 +24,6 @@
 import org.elasticsearch.cluster.LocalMasterServiceTask;
 import org.elasticsearch.cluster.NotMasterException;
 import org.elasticsearch.cluster.block.ClusterBlockException;
-import org.elasticsearch.cluster.coordination.FailedToCommitClusterStateException;
 import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.ProcessClusterEventTimeoutException;
@@ -36,7 +35,6 @@
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.util.CollectionUtils;
-import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
 import org.elasticsearch.core.SuppressForbidden;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.index.IndexNotFoundException;
@@ -233,21 +231,13 @@ public void onFailure(Exception e) {
                             )
                         );
                     } else {
-                        final Level level = isExpectedFailure(e) ? Level.TRACE : Level.ERROR;
+                        final Level level = e instanceof NotMasterException ? Level.TRACE : Level.ERROR;
                         logger.log(level, () -> "unexpected failure during [" + source + "]", e);
-                        assert isExpectedFailure(e) : e; // task cannot fail, nor will it trigger a publication which fails
+                        assert e instanceof NotMasterException : e; // task cannot fail, nor will it trigger a publication which fails
                         // TransportMasterNodeAction implements the retry logic, which is triggered by passing a NotMasterException
                         listener.onFailure(e);
                     }
                 }
-
-                static boolean isExpectedFailure(Exception e) {
-                    return e instanceof NotMasterException
-                        || e instanceof FailedToCommitClusterStateException
-                            && e.getCause() instanceof EsRejectedExecutionException esre
-                            && esre.isExecutorShutdown();
-                }
-
             });
         }
     }