Metastore: MetaStoreDirectSql.ensureDbInit has some slow DN calls which might need to be run only in test env

MetaStoreDirectSql.ensureDbInit has the following 2 calls which we have observed taking a long time in our testing:

initQueries.add(pm.newQuery(MNotificationLog.class, "dbName == ''"));
initQueries.add(pm.newQuery(MNotificationNextId.class, "nextEventId < -1"));

In a production environment, these tables should be initialized using schematool, however in a test environment, these calls might be needed.