- Move activitySleptLocked, checkReadyForSleepLocked, mGoingToSleepActivities, mGoingToSleep, mSleepTimeout from ActivityStack to ActivityStackSupervisor. - Fix bug that was causing mGoingToSleepActivities to always be empty. - Add more debug logging. Change-Id: Ibd57bd49bf6f468567571b390f3051faaeee1aa1