fix: check pdb under agent

[mattsre]

⚙️ Issue

Ticket/s: N/A

⚙️ Change

Change Type: bug fix

✅ Fix

The PDB object lives under agent in values.yaml. This check mistakenly checks the root .Values rather than .Values.agent and will cause a release with .Values.agent.pdb.create: true to fail with the following error:

failed to create chart from template: template: container-agent/templates/pdb.yaml:11:14: executing "container-agent/templates/pdb.yaml" at <.Values.pdb.maxUnavailable>: nil pointer evaluating interface {}.maxUnavailable

[ryanwohara]

Thank you!