Rollbacks shouldn't be removed when it session expires (1/n)

Once a rollback is made available, the status of its associated session
no longer matters.

Bug: 185132440
Test: Will be added in next CL
Test: atest StagedRollbackTest
Change-Id: I3c2b718905d2d7619d6f299ee5402fd858de030e
1 file changed