Confusing error message when using invalid credentials in ProviderConfig

[AaronME]

What happened?

Received the following error while attempting to deploy a resource using provider-jet-gcp:

{"error":"invalid_grant","error_description":"Invalid JWT Signature."}

How can we reproduce it?

The problem turned out to be a ServiceAccountKey which had been deleted in the console.

To reproduce:

• Create a serviceaccountkey
• Download the credentials.json
• Configure a secret and providerConfig with this credentials.json file
• Delete the serviceaccountkey in the gcp console
• Attempt to provision a resource

Creating a new key and updating the secret cleared the error.

What environment did it happen in?

Crossplane version: 1.6.1-up.1
Provider version: v0.2.0-preview