Fix type confusion in avdt_msg.cc am: 359bdee1 am: 7dac70b3

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/29817244



Change-Id: Ie7e46772342ad0b6ba7f0d2aacf97f37d32c9e23
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>