Hearing Aid State Machine without native interface

This is the state machine in Java layer. The native interface is not
hooked up yet.
It cannot handle native connect/disconnect event.

Bug: 69623109
Test: compilation and instrumentation test
Change-Id: I1f97539c6a8899fe6c2984d3b1fcd7466e88b00c
Merged-In: I1611c4c63757876a8956e1997d5a29104adbfa06
(cherry picked from commit 3e1b61a6f8397046cb2a65e20ba251bfdf343444)