bass: Fix broken test cases

This CL adopts test cases for implementation of Service, State Machine
of Broadcast Assistant.

Tag: #feature
Bug: 291879310
Test: atest com.android.bluetooth.bass_client.BaseDataTest
Test: atest com.android.bluetooth.bass_client.BassClientServiceTest
Test: atest com.android.bluetooth.bass_client.BassClientStateMachineTest
Change-Id: I77c8772fc3de0f043552ec07b9a76036bf9e0b7c