configConnector GKE addon config added to cluster resource

[venkykuberan]

Release Note Template for Downstream PRs (will be copied)

fixes - https://github.com/terraform-providers/terraform-provider-google/issues/6300

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 2 files changed, 22 insertions(+), 8 deletions(-))
Terraform Beta: Diff ( 3 files changed, 65 insertions(+), 9 deletions(-))

[nat-henderson]

I'd use "project", unless this is in use elsewhere in the file.

[venkykuberan]

pid was used in other tests, just used the same to be consistent

[nat-henderson]

If you could let me know how you've tested this I'll merge! :)

[venkykuberan]

If you could let me know how you've tested this I'll merge! :)
ran the acceptance tests with
1) initialize the resource with addon configConenctor - false
2) update the resource with addon configConenctor - true

Tests passed which i believe it confirms the property is settable on the resource and resource is importable