Add gnustl_shared library.

Add gnustl_shared library.

For support Android API earlier than level 18 (Android 4.3)

Change-Id: I7b1eefd05a9ff1c8b7f93fadc7596920531725e7
Signed-off-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/11483
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: jihwan seo <jihwan.seo@samsung.com>
Reviewed-by: Dave Thaler <dthaler@microsoft.com>
Reviewed-by: Larry Sachs <larry.j.sachs@intel.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>