Cannot update b/g application labels in v3

[sleungcy]

We are unable to modify the application labels since introduction of v3.

terraform-provider-cloudfoundry/cloudfoundry/managers/v3appdeployers/bluegreen_strategy_v3.go

Line 109 in 217682b

_ = metadataUpdate(appResp.App.GUID, appMetadata, s.rawClient, metadata)

The code here copies the labels from the venerable app over to the new version of the app.. this prevents the application from updating to new labels when the labels are changed.

I believe this code was copied over from the v2 code from here:
https://github.com/cloudfoundry-community/terraform-provider-cloudfoundry/blob/main/cloudfoundry/managers/appdeployers/bluegreenv2_strategy.go#L104

Basing on the comment:

// copy metadata from original app since they do
// not carry over in the ccv2.Application data structure

This code would not be needed in bluegreen_strategy_v3.go, as we already migrated over to ccv3.Application.

[sleungcy]

changes proposed