LE audio unicast / broadcast dynamic switch refactor

Refactor LE audio dynamic switch logic. Add an new properties to
switch le audio mode as broadcast enabled to reduce to skip the broadcast
enabled without unicast enabled scenairo for simplicity

Bug: 316005152
Bug: 317516854
Test: m com.android.btservices
Change-Id: I4df9cb5f12fddfdc43ffc7bfd67f35565c9d7a59