Fix flaky test MasterServiceTests.testClusterStateUpdateLoggingWithDebugEnabled (opensearch-project#15204)

* Fix test MasterServiceTests.testClusterStateUpdateLoggingWithDebugEnabled

Signed-off-by: Sumit Bansal <[email protected]>

Author: sumitasr

server/src/test/java/org/opensearch/cluster/service/MasterServiceTests.java

@@ -534,8 +534,8 @@ public void onFailure(String source, Exception e) {
                 });
                 assertBusy(mockAppender::assertAllExpectationsMatched);
                 // verify stats values after state is published
-                assertEquals(1, clusterManagerService.getClusterStateStats().getUpdateSuccess());
-                assertEquals(0, clusterManagerService.getClusterStateStats().getUpdateFailed());
+                assertBusy(() -> assertEquals(1, clusterManagerService.getClusterStateStats().getUpdateSuccess()));
+                assertBusy(() -> assertEquals(0, clusterManagerService.getClusterStateStats().getUpdateFailed()));
             }
         }
     }
@@ -699,8 +699,8 @@ public void onFailure(String source, Exception e) {
                 });
                 assertBusy(mockAppender::assertAllExpectationsMatched);
                 // verify stats values after state is published
-                assertEquals(1, clusterManagerService.getClusterStateStats().getUpdateSuccess());
-                assertEquals(0, clusterManagerService.getClusterStateStats().getUpdateFailed());
+                assertBusy(() -> assertEquals(1, clusterManagerService.getClusterStateStats().getUpdateSuccess()));
+                assertBusy(() -> assertEquals(0, clusterManagerService.getClusterStateStats().getUpdateFailed()));
             }
         }
     }