HFP: Fix missing sco events and masked events

* SCO events have secondary actions that need to be handled
* Also remove event masking, which is no longer needed

Bug: 167349211
Bug: 159815595
Tag: #refactor
Test: compile & verify Bluetooth connections are working
Change-Id: If8d3aa873b55b5d6936c16766fd6c1c49749002d