java.nio.channel.FileLock test

The tests check the behaviour of FileLock when more than one processe or
thread try to hold the file lock.

The FileLock should return null if the multiple processes try to obtain
the lock, however, it should raise OverlappingFileLockException if the
lock is already held by the same runtime.

Bug: 27186422
(cherry-picked from commit f16ac2dcde20737e2f437d5c8cd5a321c0c38273)
Change-Id: I97184d7735ad05a9b88cf8ee7dbc76177b0210d2
5 files changed