GTBS: Respect inband configuration

This patch just takes inband ringtone flag from the LeAudioService.
For now, even it is done per device, it will always return single value.
It is done like that as a preparation for following patch which will
alow to handle different configuration per device

Bug: 242685105
Test: atest BluetoothInstrumentationTests
Tag: #feature

Change-Id: I76c02e87b092bbb00070a3543c9a22e46823de85