[Linphone Android] 应答请求

接受呼叫请求：

    public int acceptCall(){        LinphoneCall call = mLinphoneCore.getCurrentCall();        try{            mLinphoneCore.acceptCall(call);            mLinphoneCore.enableSpeaker(true);        }catch(LinphoneCoreException exception){            Log.d(TAG, exception.toString());            return -1;        }        stopRinging();        return 0;    }