Add unit tests for FileChannel#lock #tryLock

The change adds more test for FileChannel #lock and #tryLock.

The change also includes test for overlapping lock using different file
channels.

Bug: 27186422
(cherry-picked from commit fb376ca44c4c3ed1d53b93f32712c4efc9490a76)
Change-Id: Ib040bb28d8ce8417d2cd8fb2c81a9d50519e8fde
1 file changed