* Delete expired segments in expired segments service using metainfo
loop
* Add test to verify expired segments service deletes expired segments
* Ignore expired segments in checker observer
* Modify checker tests to verify that expired segments are ignored
* Ignore expired segments in segment repairer and drop from repair queue
* Add repair test to verify that a segment that expires after being
added to the repair queue is ignored and dropped from the repair queue
Change-Id: Ib2b0934db525fef58325583d2a7ca859b88ea60d
