E2 VMs in GKE examples

[danawillow]

https://cloud.google.com/blog/products/compute/google-compute-engine-gets-new-e2-vm-machine-types
https://cloud.google.com/compute/docs/machine-types

We may also want to use them for GCE examples too while we're here, but this issue specifically is for using them in GKE examples.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

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