Update Bluetoot Audio HAL Target Test

Since we change the design of loading LE Audio Capabilities in BT
Audio HAL, we update the VTS test to make sure no matter a device
supports LE Audio Offload or not, it can pass all tests that they
should pass.
Also, update vts test to match C++ coding style.

Bug: 248181252
Test: atest VtsHalBluetoothAudioTargetTest
Change-Id: Ie46c86663e0a22627c324f96360063cd4d4874e4