Move destructor after stack flag in main/shim/::Stack::Stop()

Legacy shim acl releases controller resources

Bug: 166280067
Tag: #refactor
Test: act.py -tc BleCocTest
Test: ble paired 2 phones
Test: classic paired Bose SoundLink

Change-Id: I78ccd0d541f82bfec86180f2c2dd0521af651b6d