Always enable apk-in-apex before the apex (2/n)

To keep a rollback object in a consistent state, an apex shouldn't be
enabled (for rollback) until all its embedded apk-in-apex are enabled
successfully.

Bug: 149352598
Test: test RollbackTest StagedRollbackTest
Change-Id: I4d0208118050f948675093f4ed67de8ae148f41b