[BUG] handle k8s lowecase Kind properly

[ryanzhang-oss]

Describe the bug

The k8s built-in restMapper treats the Kind as case insensitive. We need to see if we should block that or treat the Kind as case insensitive too in our code when we compare the Kind in our resource selector.

Environment

Please provide the following:

• Hub cluster details
• Member cluster details

To Reproduce

Steps to reproduce the behavior:

Expected behavior

TBD

Screenshots

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Additional context

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[Fei-Guo]

https://github.com/kubernetes/kubernetes/blob/0f37b3120643580f632ca12d3e174e7ec447948c/staging/src/k8s.io/client-go/restmapper/discovery.go#L114

Find the code that put both the lowercase and uppercase kind into mapper. Don't know why though.