Invoke Lambda stage configuration fails when setting region

[dogonthehorizon]

Before submitting your issue, please make sure you provide as much details for the following questions as possible:

• High level summary / overview of the issue (think TLDR)
  • Stage config fails when configuring the Invoke Lambda stage and attempting to set the region. Unable to modify settings without updating the config from the Edit JSON dialog.
• Details of the environment.
  • What is the version of the plugin?
    • 1.0.1
  • What is the version of spinnaker?
    • 1.27.0
• Current behavior
  • Detailed description of the problematic behavior seen
    • See the attached GIF: https://s.armory.io/ApuE7RvJ
  • Which stage is failing?
    • AWS Lambda Invoke
  • Which task within the stage is failing?
    • Configuration
  • Include a screen shot from detailed task executions for the failing stage
    • Console shows this error: https://s.armory.io/YEuP5X6D
  • Include error logs where possible
• Expected behavior (Detailed description of the expected behavior and how it is different from the current behavior).
• Steps for how to reproduce (Please include Spinnaker JSON blobs and parameter values as reference where applicable)
• Any applicable screenshots for the failure you see