Fix helm chart resolution issue

[t0yv0]

Proposed changes

Fixes issue with helm chart not found. Originally showed up in examples repo for helm.

Related issues

• classic-azure-ts-aks-helm failing during pulumi up examples#938

Test/debug notes

I was reproducing pulumi/examples#938 with a custom-built pulumi-resource-kubernetes (from master) that included instrumentation to spew out the failing Chart parameter, this is what I got:

(*provider.chart)(0xc000603c80)({
 opts: (provider.HelmChartOpts) {
  HelmFetchOpts: (provider.HelmFetchOpts) {
   CAFile: (string) "",
   CertFile: (string) "",
   Destination: (string) "",
   Devel: (bool) false,
   Home: (string) "",
   KeyFile: (string) "",
   Keyring: (string) "",
   Password: (string) "",
   Prov: (bool) false,
   Repo: (string) (len=34) "https://charts.bitnami.com/bitnami",
   UntarDir: (string) "",
   Username: (string) "",
   Verify: (bool) false,
   Version: (string) ""
  },
  APIVersions: ([]string) <nil>,
  Chart: (string) (len=6) "apache",
  IncludeTestHookResources: (bool) false,
  Namespace: (string) "",
  Path: (string) "",
  ReleaseName: (string) (len=6) "apache",
  Repo: (string) (len=7) "bitnami",
  Values: (map[string]interface {}) <nil>,
  Version: (string) (len=5) "1.0.0"
 },
 chartDir: (string) (len=8) "chartdir",
 helmHome: (*string)(<nil>)
})

So presumably the client was passing Repo=bitnami and also HelmFetchOpts.Repo=https://charts.bitnami.com/bitnami together.

Is this a client fault or the pulumi-resource-kubernetes fault? The PR assumes the input is valid but pulumi-reosurce-kubernetes should process it differently. If the input is invalid, let us instead fix the client and harden pulumi-resource-kubernetes to warn appropriately.

[lblackstone]

🎉