Improve HeadsetServiceTest

inband ringtone is only opened when a device is active device. 
When a device is not active, even it indicates inband ringtone support, SCO won't be connected because it is not active. 

Bug: 346498545
Bug: 349318724
Change-Id: I01ea46211f150c8cef08b5c7c5a19227b7b2ea6a
Test: atest HeadsetServiceTest
Flag: com.android.bluetooth.flags.update_active_device_in_band_ringtone