Copy to std::string when parsing LE audio config am: 37681976

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/17958688



Change-Id: Id65198b5a330b960b8c87c08ada6a3f1d213de23
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>