Changed the property of /oic/ping resource

Changed the property of /oic/ping resource

The resource property of /oic/ping is changed from DISCOVERABLE to
NONE.

Change-Id: Ibb1d8d80f859fdbb34a75a22b19bd66979fa6b13
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/13439
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
Reviewed-by: jihwan seo <jihwan.seo@samsung.com>
(cherry picked from commit a23f545b5ed285d51e34f4faea939db847959e92)
Reviewed-on: https://gerrit.iotivity.org/gerrit/13601