Automatic merge from submit-queue (batch tested with PRs 63272, 63782, 63715, 63811, 63803). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add support for GCP charm

**What this PR does / why we need it**: Continuing from #62354, add support for Juju charms to connect to GCP integration charm to automatically manage IAM labels and roles, and cloud-provider setting for GCE.

**Release note**:
```release-note
NONE
```