onap: Create periodic jobs to run on Xerces cloud

This change creates 2 new jobs to run on Xerces cloud and also
changes how the parent/upstream jobs are named. Since clouds name
images, flavors, and public networks differently, the jobs use
corresponding heat environment files based on cloud and distro
names in order to be able to create stacks with the right parameters.

Currently only City jobs are automatically triggered and Xerces
jobs require to be triggered manually.

Please note that once this change gets merged, existing parent/upstream
jobs will be removed and new ones will be created with the new name.

Also oom-hc job was not running for a month due to a bug which is
fixed as well.

Change-Id: I063ea2de482aeb293409fb27e0927d6397ffbd98