reorder config application

[KowalczykBartek]

Description

Because of current order of filters:

http_filters : [ext_auth, envoy.filters.http.cors, envoy.filters.http.router]

when ext_auth returns 4xx (or it fails because of whatever other reasons) the cors handler is not called and no cors headers are injected (for example access-control-allow-origin) - because of that browser is not able to handle such response gently.
I first tested if reordering of these filters will help, using plain envoy, and following configuration gave me expected result - cors where injected even if ext-auth returned 4xx (it makes sense because cors is handled first)

http_filters:
  - name: envoy.filters.http.cors
  - name: envoy.filters.http.ext_authz
    typed_config:
      "@type": type.googleapis.com/envoy.extensions.filters.http.ext_authz.v3.ExtAuthz
      http_service:
          server_uri:
            uri: 172.17.0.2:8080
            cluster: ext-authz
            timeout: 2.25s
  - name: envoy.filters.http.router

then I tried do the same with Ambassador Intermediate Representation - and It also works.

Testing

Tested on stage env (kubernetes).

Checklist

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