Revert "Change the routing path of bluetooth headset connections."

Changes the way to bind to HeadsetService. Changes are causing
memory leaks and stability issues.

This reverts commit e8b98925.

CRs-fixed: 934279
Change-Id: Ic2820d2e51581a6c9987028265a90fccd64e3c68

Bluetooth: Fix for CTS failure

CTS checks for caller identity. Return true if foreground user
is calling BT APIs.

CRs-fixed: 939173
Change-Id: I9b7636e9769c071363a3a402c447c24281c8cc9d

BT: Allow user processes to bind to HeadsetService in guest login

In guest login, allow binding to HeadsetService for user processes.

CRs-Fixed: 959566
Change-Id: I7d35b89ddc20ebc7db9dcffb21a715108d842923