Add stack/acl/btm_acl::acl_disconnect_from_handle

Handles are in progress of being all recaptured, but
expose this as a replacement for the after_role_switch
as that is an internal ACL implementation decision.

Towards readable code

Bug: 163134718
Tag: #refactor
Test: gd/cert/run --host

Change-Id: I88c15fd03a6fffe41178523fba4979ca70e4fa19