Upgrading Red Hat 3scale API Management from 2.4 to 2.5 On-premises fails on the step "Add the current values of the MySQL user and password into the system-database secret"

Issue

• While upgrading from 2.4 to 2.5, the following command:

  $ oc patch secret/system-database -p "{\"stringData\": {\"DB_USER\": \"${RESULT_MYSQL_USER}\"}}"
  

  Results in the following error:

  Error from server (NotFound): secrets "system-database" not found
  

• The command $ oc get secret system-database -o yaml returned the below output:

  Error from server (NotFound): secrets "system-database" not found