Properly init bta::av::bta_av_aact message structures 5/20 am: 9a45b114 am:...

Properly init bta::av::bta_av_aact message structures 5/20 am: 9a45b114 am: cb0fbfdd am: 1640304d

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/2323922



Change-Id: Ie11f39f3ae01f8890d2559a8e242464fee3162f5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>