Not able to revert back after selecting a role in the policy workflow

### Problem description
In the policy workflow's `Roles` block, if the user selects wrong role by mistake then there is no way for the user to go back and change the role. I have tried implementing a few ways in which the assigned role can be reverted but it does not seem to work.

### Step to reproduce
Steps to reproduce the behavior:
1. Go to a policy which has `Roles` block configured

2. Run/Dryrun the policy and select a role

3. Once selected you will see the next screen and there is no way to revert the role

### Expected behavior
Ideally I want the user the have an option for them to go back and be able to select a different user role. Is it possible with the current infrastructure and if so then how can it be implemented?