Availability requirement update is initially disabled on Edit PodDisruptionBudget page

Availability requirement updates is disabled on Edit PDB page, also when user tries to edit, it clears the current value so that user has no idea what's the current settings

4.14.0-0.nightly-2023-04-03-211601

Always

1. Goes to deployment page -> Actions -> Add PodDisruptionBudget
2. on 'Create PodDisruptionBudge' page, set following fields and hit 'Create'
Name: example-pdb
Availability requirement:  maxUnavailable: 2
3. Make sure pdb/example-pdb is successfully created
$ oc get pdb
NAME          MIN AVAILABLE   MAX UNAVAILABLE   ALLOWED DISRUPTIONS   AGE
example-pdb   N/A             2                 2                     99s
4. Goes to deployment page again,  Actions -> Edit PodDisruptionBudget

'Availability requirement' value is disabled from editing by default, when user click 'maxUnavailable', the value is set to empty(user has no idea what's the original value)

when editing PDB, we should load the form with current value and user should have permission to update the values by default