Add a test for V100 against the GKE staging endpoint.
Add a test for V100 against the GKE staging endpoint.

We use 8 V100 per node because that's the supported configuration currently.

GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid