Fix an integer overflow bug in avdt_msg_asmbl am: bf9449a7 am: df75554b am: 5e673575

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/23152778



Change-Id: Ie9722a2ff30152094bbd86786e0c21c75edf1602
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>