In Drydock, yield for reclaiming resources in the "released" state

Summary: Ref T13677. This was an accidental change in D21807: when reclaiming a resource, wait for it to be completely destroyed before allowing a lease to reclaim another resource.

Test Plan: Reverts accidental behavior change in D21807.

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13677

Differential Revision: https://secure.phabricator.com/D21809