Using a hyphenated cluster name breaks bigquery naming convention

**Describe the bug**
Using a hyphenated cluster name breaks the BigQuery naming convention. BigQueryDataset does not support hyphens.

**To Reproduce**
Set a hyphenated cluster name in solutions/sandbox-gke/setters.yaml -> cluster-name: my-sandbox and deploy the solution.

**Error msg**
Update call failed: error applying desired state: summary: googleapi: Error 400: Bigquery_destination.dataset_id must be alphanumeric (plus underscores)., badRequest

**Files affected**
solutions/sandbox-gke/private-gke/gke/bigquerydataset.yaml
solutions/sandbox-gke/private-gke/gke/containercluster.yaml

**Expected behavior**
Successful deployment of the BigQuery dataset and container cluster.

I suggest using a static name instead of using setters:
`# kpt-set: ${cluster-name}gkemetering`

solutions/sandbox-gke/private-gke/gke/bigquerydataset.yaml
solutions/sandbox-gke/private-gke/gke/containercluster.yaml