Use encrypted link for avdtp and avctp channels

This is a backport of the AOSP changes for b/345258562.

Test: mmm packages/modules/Bluetooth
Bug: 345258562
Ignore-AOSP-First: security
Tag: #security
Merged-In: Ic5c728abddb43d34ecbd0be7fb1e0f19f2eb291b
Change-Id: I4ef23f9dec4aaae6a526c11a7c2489159bd7fdf8