bass_client: If PAST is not supported inform sink to sync with no PAST

This modifies Add Source handling path, instead of `0x00: Do not
synchronize to PA` let's use `0x02: Synchronize to PA - PAST not
available` if PAST is not supported on device.

Tag: #feature
Test: atest BassClientServiceTest
Test: atest BassClientStateMachineTest
Bug: 323343735
Bug: 316005152
Change-Id: I5064fc66352b54535de9685559ebceadb262d0ef