Support gcp cluster

[sbernauer]

I just tried it with a gcp cluster:

(⎈ |gke_engineering-329019_europe-central2-a_stackablectl:default)➜ demo stackablectl operator install hbase
[INFO ] Installing hbase operator
panic: Kubernetes cluster unreachable: no Auth Provider found for name "gcp"goroutine 17 [running, locked to thread]:
main.go_install_helm_release({0x557af8269930, 0xe}, {0x557af8273e20, 0x1c}, {0x557af68f7488, 0x8}, {0x557af8273a00, 0x7}, 0x1?)
/home/runner/work/stackablectl/stackablectl/go-helm-wrapper/main.go:32 +0x1da
[1] 70555 IOT instruction (core dumped) stackablectl operator install hbase
(⎈ |gke_engineering-329019_europe-central2-a_stackablectl:default)➜ demo