Use mecached-custom package to package service file to system
folder instead of platform-utils.
Basic deployment test pass and service file status check pass.
Story: 2004108
Task: 27517
Depends-on: https://review.openstack.org/#/c/614085/
Change-Id: Ic66f077159be2f21caa6e8e68241aae65b9f2245
Signed-off-by: zhipengl <zhipengs.liu@intel.com>