[BUG] Fix unknown host temporally

[cheyang]

What is your environment(Kubernetes version, Fluid version, etc.)

Describe the bug

Some times we faced:

2021-01-02 14:19:35,799 WARN  GrpcBlockingStream - Received error io.grpc.StatusRuntimeException: UNAVAILABLE: Failed to read block ID=689577132058 from tiered storage and UFS tier: abc.oss-cn-shanghai-internal.aliyuncs.com
[ErrorCode]: UnknownHost
[RequestId]: Unknown for stream (Zero Copy GrpcDataReader)
2021-01-02 14:19:35,800 WARN  AlluxioFileInStream - Failed to read block 689577132058 of file /abcbenchmark/demo_data/all/train/from worker WorkerNetAddress{host=10.219.6.194, containerHost=, rpcPort=20002, dataPort=20002, webPort=20003, domainSocketPath=, tieredIdentity=TieredIdentity(node=10.219.6.194, rack=null)}, will retry: Failed to read block ID=689577132058 from tiered storage and UFS tier: abc.oss-cn-shanghai-internal.aliyuncs.com
[ErrorCode]: UnknownHost
[RequestId]: Unknown (Zero Copy GrpcDataReader)

We can leverage https://kubernetes.io/zh/docs/concepts/services-networking/add-entries-to-pod-etc-hosts-with-host-aliases/

What you expect to happen:

How to reproduce it

Additional Information

[xieydd]

Any progress?