AdapterService, use RemoteCallbackList instead of a set

RemoteCallbackList are made for tracking remote callback by using a
linkToDeath and automatically removing dead binder from the list. It
also works as a set by not adding multiple times the same binder.

Bug: 363936742
Test: atest CtsBluetoothTestCases
Flag: Exempt, callback registration pattern is used widely
Change-Id: I039e1c4a0e0e754d61ce209172c075bebcb91f99