During normal sharding, parent shard and child shard ranges
may have transient overlaps which will disapear when done.
To avoid this transient overlap shows up in the warning log,
when sharder audits root container, it will not emit
'overlapping ranges in state ...' warning when overlapping
shard ranges are parent-children during the past time period
of reclaim_age.
Change-Id: I88bce3c178923457e3887790fa58aad56086b1e6
230b467af0