[java] Fix a scan bug which will read repetitive rows.

When isFaultTolerant is true, from 2nd ScanRequest, in its response
callback function, lastPrimaryKey is not updated.

In common scenarios, when tablet server hosting the leader replica
restarts, Scanners will read rows from the first
ScanResponse's lastPrimaryKey, that will return some repetitive rows.

Change-Id: I4d6be9df10c1a45cd971b52a0351028c1f5a023f
Reviewed-on: http://gerrit.cloudera.org:8080/18420
Tested-by: Kudu Jenkins
Reviewed-by: Andrew Wong <awong@cloudera.com>
4 files changed