Enabled CoAP/TCP on android platform

Enabled CoAP/TCP on android platform

currently, coap/tcp can be supported on linux platform.
so I modified the code to support Android platform.

Change-Id: Ia9a9e36939f848b98393648968ddcfacfa7ce564
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Signed-off-by: jihwan.seo <jihwan.seo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/3411
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Naga Ashok Jampani <jn.ashok@samsung.com>
Reviewed-by: Jon A. Cruz <jonc@osg.samsung.com>