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
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:d5ff4150cb9e97eafaac7a8e32176bd5048a5fd2)
Merged-In: I4ef23f9dec4aaae6a526c11a7c2489159bd7fdf8
Change-Id: I4ef23f9dec4aaae6a526c11a7c2489159bd7fdf8