Creating socket everytime when network bearer changes (#285)

Creating socket everytime when network bearer changes (#285)

[CONPRO-1269] Creating socket everytime when network bearer changes

Socket was created only once but changed the logic for creating on every network change
When we are switching WifiAP or disconnect/connect again then we are not able to send unicast data from android side . It gives network unreachable error. So to avoid that we are closing and creating sockets again.

https://github.sec.samsung.net/RS7-IOTIVITY/IoTivity/pull/285
(cherry picked from commit 285875048bda46b6ac1a742c25849d70234d7cd1)

Change-Id: I5af2a47c925d03b50b5802229754f7f4d317be76
Signed-off-by: Kush <kush.agrawal@samsung.com>
Signed-off-by: Amit KS <amit.s12@samsung.com>