ASACORE-994: enforce correct destruction order

Interface descriptions should be destroyed after the transportList since
the latter triggers destruction of end-points which in turn triggers
destruction of ProxyBusObjects which need those interfaces (they call
GetInterface on the BusAttachment.

Change-Id: I83480eaa1bb20fc887e795e1b0babdbbc5e3af44
Signed-off-by: Meggan Ehret <meggan@qeo.org>
Merge "ASACORE-994: enforce correct destruction order"