Fix block manager UI display issue when enable spark.cleaner.ttl

When spark.cleaner.ttl is enabled, RDD id got from BlockManger's block id may not have correspondence in SparkContext's `persistentRdds`, `persistentRdds` has already clean up this RDD, which will make `val rdd = sc.persistentRdds(rddId)` throw `NoSuchElementException` . So here cleaned RDD should be filted out.