[Openstack-containers][OSP12][RFE]: Docker environment files  that required for overcloud deployment should be created during undercloud install or by installing RPM . 


Description  : 
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In order to run deployment of overcloud with containers in osp12, the deployment command requires to point a docker environment file such : docker-osp12.yaml 
which we download and change, this file is also dynamic and changes all the time because there are new containers which getting build and should be include ,

this RFE request is to have these environment files created by the undercloud install - Or be automatically created by RPM  ( such: rhos-release ) 


the files are : 
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(1) container_images.yaml

(2) docker-osp12.yaml