Change in serviceAccountName: parameter doesn't rebuild the statefulset

Steps to reproduce:

1) Have service account named "firstAccount" configured in  your namespace

2) Don't have service account named "secondAccount" configured in your namespace

3) Deploy CR with "secondAccount" as serviceAccountName

This, sa expected, fails with event saying "service account named secondAccount does not exist"

4) Try to fix it by using correct account in yaml with`oc apply`

5) Expected: statefulset is fixed, account name replaced

Actual: statefulset is still broken, nothing happens

workaround: delete original CR and recreate it again.

see ENTMQBR-3620