Fix CAGetNetworkInfo support to getting ifindex

Fix CAGetNetworkInfo support to getting ifindex

Current CAGetNetworkInfo function always set ifindex as 0.
Change logic to set ifindex parsed from platform.

Change-Id: I98d53dc0fe4a666b6c9eaf8900d1e68ee4c925f2
Signed-off-by: bg.chun <bg.chun@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/13955
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jaewook Jung <jw0213.jung@samsung.com>
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>