WHAT
Before running the RHOAM upgrade the "corrupted" users have to be present on the cluster. See step 3. of N02b test case:

https://github.com/integr8ly/integreatly-operator/blob/c84e1c4182759a595b7bd56e28d2e436141b25d1/test-cases/tests/upgrade/n02b-upgrade-rhoam.md

HOW
Create a stage that creates such users. Should be skippable. In both addon-flow and master pipelines.

Use existing tests to create users and log into 3scale (B01B and H07 respectively) - some updates might be needed to change usernames for this purpose. Ideally iva passing some env var. The tests can be triggered by runFunctionalTests.groovy or via `make test/e2e/single` (former preferred). Corrupt the users afterwards as described in the test case (oc commands are there)

TESTS
N/A

DONE
 * stage exists and the corrupted users are creates on the cluster if stage is not skipped