SequenceFile.Writer should implement StreamCapabilities

Following exception is thrown whenever we invoke ProtoMessageWriter.hflush on S3 from Tez, which internally calls org.apache.hadoop.io.SequenceFile$Writer.hflush ->  org.apache.hadoop.fs.FS DataOutputStream.hflush -> S3ABlockOutputStream.hflush which is not implemented and throws java.lang.UnsupportedOperationException. 

bdffe22d96ae [mdc@18060 class="yarn.YarnUncaughtExceptionHandler" level="ERROR" thread="HistoryEventHandlingThread"] Thread Thread[HistoryEventHandlingThread, 5,main] threw an Exception.^Mjava.lang.UnsupportedOperationException: S3A streams are not Syncable^M at org.apache.hadoop.fs.s3a.S3ABlockOutputStream.hflush(S3ABlockOutputStream.java:657)^M at org.apache.hadoop.fs.FS DataOutputStream.hflush(FSDataOutputStream.java:136)^M at org.apache.hadoop.io.SequenceFile$Writer.hflush(SequenceFile.java:1367)^M at org.apache.tez.dag.history.logging.proto.ProtoMessageWriter.hflush(ProtoMessageWr iter.java:64)^M at org.apache.tez.dag.history.logging.proto.ProtoHistoryLoggingService.finishCurrentDag(ProtoHistoryLoggingService.java:239)^M at org.apache.tez.dag.history.logging.proto.ProtoHistoryLoggingService.han dleEvent(ProtoHistoryLoggingService.java:198)^M at org.apache.tez.dag.history.logging.proto.ProtoHistoryLoggingService.loop(ProtoHistoryLoggingService.java:153)^M at java.lang.Thread.run(Thread.java:748)^M

In order to fix this issue we should implement StreamCapabilities in SequenceFile.Writer. Also, we should fall back to flush(), if hflush() is not supported.