Make Android Headtracker Service a restricted service

Android Bluetooth GATT prevents applications from accessing managed
GATT services like HOGP, LE Audio profiles, etc. Android Headtracker
Service is a managed service and applications should not be able to
read/write its characteristics.

Test: mmm packages/modules/Bluetooth
Test: Manual | connect with an earbud with Android Headtracker Service
using a GATT client app, try reading the AHS characteristics.
Flag: EXEMPT bugfix
Bug: 350085606

Change-Id: I94c3043ac807c74b12580d0e3719e79b62d67c46