audiopolicy: fix notification tone during call not stopped after call ended

Due to wrong func isInCall() called in setPhoneState() after phone state
changed, notification tone won't be stopped after call ended.
Correct the func to isStateInCall(int state).

Change-Id: I607e96f1fecdcf37d8865af2aa9b4cbd4450aca6
CRs-Fixed: 978534