Issue 5216 : Line get meesy if missed a call

When A calls B , and B doesnt picks up ,B should be ONHOOK state ,else next call will not reach since it assumes its busy. This fix has fixed the other bug of the timer getting started when call ends and even after ONHOOK howler was played and can we heared on OFFHOOK.

Test cases tested:

1- Keep phone off Hook , unobtainable -silence -howler seq should follow 2- Call A to B , B doesnt pick up ,Call B again ,B should ring .(Busy issue is fixed) 3- Call A to B , call is connected ,A hangs up ,B should hear unobtainable -silence - howler sequence) 4- Call hold 5- 3 party call