Bass: Fix BIS sync state channel map

There are 31 bits available in the channel map due
to 0xFFFFFFFF being a special value. This allows for
31 channels indexed from 1 to 31.

That means bit 0 is for channel 1 and so forth.

Bug: 240885642
Test: manual - logs verification
Tag: #feature
Change-Id: Ib48812123d29ee4500261b46d1987d6e9469c632
Merged-In: Ib48812123d29ee4500261b46d1987d6e9469c632
(cherry picked from commit 7de61c7a)