Revert "Merge branch 'use-bitnami-postgres-for-test-template' into 'master'"

What does this MR do?

Reverts !44329 (merged). See #263864 (closed)

Not all tags used with postgres is present with bitnami/postgresql

tkgl:gitlab tkuah$ docker pull bitnami/postgresql:11.8
Error response from daemon: manifest for bitnami/postgresql:11.8 not found: manifest unknown: manifest unknown

tkgl:gitlab tkuah$ 
tkgl:gitlab tkuah$ docker pull postgres:11.8
11.8: Pulling from library/postgres
75cb2ebf3b3c: Pull complete 
3ca6415d2bca: Pull complete 
ac08e6372a7b: Pull complete 
b4394fce95ce: Pull complete 
6edcd5da08e3: Pull complete 
3380dcb7db08: Pull complete 
c7c147d9c90d: Pull complete 
08ae47fef758: Pull complete 
fef60fa8e5fa: Pull complete 
28fde916f759: Pull complete 
6a07ef71c37d: Pull complete 
3bb87f025d35: Pull complete 
98233f2662f5: Pull complete 
64d6643e93fe: Pull complete 
Digest: sha256:05b946388d2c7eed6de8de8ffda854614b6edf1e3117ad5ccded3b87754ac024
Status: Downloaded newer image for postgres:11.8
docker.io/library/postgres:11.8