audio: Fix invalid BT A2DP interface name

The correct name is:
android.hardware.bluetooth.a2dp@1.0::IBluetoothAudioOffload

Bug: 148648456
Bug: 148648729
Bug: 148648469
Bug: 148648355
Test: DeviceBootTest.DeviceBootTest#SELinuxUncheckedDenialBootTest
Change-Id: I50d3486159f17697b06e9680b85586b1935a9ccc