Upgrade the default images from newton to ocata and update
the following configuration files to align with ocata.
event_definitions.yaml
pipeline.yaml
policy.json
api_paste.ini
Story: 2005019
Task: 29773
Change-Id: Ib0ba502215aa0fe959606f15dacf39e2cdd06fe6
Signed-off-by: Angie Wang <angie.wang@windriver.com>