Unintuitive precedence of environment over cli flags

[Kidsan]

I am having issues using kubelogin and parameterizing uses of it when in a managed pipeline environment
Due to the

kubelogin/pkg/internal/token/options.go

Line 140 in ae4b42a

func (o *Options) UpdateFromEnv() {

function, arguments passed via cli are ignored for non-obvious reasons.

Example

> AZURE_TENANT_ID=foo kubelogin get-token --tenant-id bar # tenant-id = foo

It seems to me that in cases like this --tenant-id should be prioritized.

[Kidsan]

Duplicate of #427