Install declarative config dependencies by default
Install declarative config dependencies by default

This introduces Skaffold, Kpt and Kustomize to the image with an aggregate size of ~50MB. These tools will be increasingly used for CI/CD tasks so will be good to have them in our builders.
google-octo/cloud-builders,GoogleCloudPlatform/cloud-builders,google-octo/cloud-builders,google-octo/cloud-builders,GoogleCloudPlatform/cloud-builders,GoogleCloudPlatform/cloud-builders,GoogleCloudPlatform/cloud-builders,google-octo/cloud-builders,GoogleCloudPlatform/cloud-builders,google-octo/cloud-builders,google-octo/cloud-builders,GoogleCloudPlatform/cloud-builders,GoogleCloudPlatform/cloud-builders,google-octo/cloud-builders