Changing the docs for the sign-in page config from gcpiap to gcpIap. The router is case-insensitive, so they both work, but this will make everything consistent between backend and frontend.

Signed-off-by: Brian Saltz Jr <brian.saltzjr@gocrisp.com>

docs/auth/google/gcp-iap-auth.md

@@ -77,6 +77,6 @@ backend.add(import('@backstage/plugin-auth-backend-module-gcp-iap-provider'));
 
 ## Adding the provider to the Backstage frontend
 
-See [Sign-In with Proxy Providers](../index.md#sign-in-with-proxy-providers) for pointers on how to set up the sign-in page, and to also make it work smoothly for local development. You'll use `gcpiap` as the provider name.
+See [Sign-In with Proxy Providers](../index.md#sign-in-with-proxy-providers) for pointers on how to set up the sign-in page, and to also make it work smoothly for local development. You'll use `gcpIap` as the provider name.
 
 If you [provide a custom sign in resolver](https://backstage.io/docs/auth/identity-resolver#building-custom-resolvers), you can skip the `signIn` block entirely.