Fine-granular feature flag for request body compression

[shaoxt]

Proposal

          http_filters:
          - name: envoy.filters.http.compressor
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.compressor.v3.Compressor
              request_direction_config:
                common_config:
                  enabled:
                    default_value: false
                    runtime_key: request_compressor_enabled
                  enable_on_x_header: true

With this new feature flag "enable_on_x_header: true" enabled.

Even through the global feature flag was set to "false", the compressor filter will check the request header
if the request header contains "X-Request-Compression: true", the request body will be compressed.

This will give more fine-granular control for the istio-proxy outbound traffic.

PR for #38097

Commit Message:

Additional Description:
Risk Level: Low
Testing:
Docs Changes:
Release Notes:
Platform Specific Features:
[Optional Runtime guard:]
[Optional Fixes #38097]
[Optional Fixes commit #PR or SHA]
[Optional Deprecated:]
[Optional API Considerations:]

[repokitteh-read-only]

Hi @shaoxt, welcome and thank you for your contribution.

We will try to review your Pull Request as quickly as possible.

In the meantime, please take a look at the contribution guidelines if you have not done so already.

🐱

Caused by: #38098 was opened by shaoxt.

see: more, trace.

[repokitteh-read-only]

CC @envoyproxy/api-shepherds: Your approval is needed for changes made to (api/envoy/|docs/root/api-docs/).
envoyproxy/api-shepherds assignee is @abeyad
CC @envoyproxy/api-watchers: FYI only for changes made to (api/envoy/|docs/root/api-docs/).

🐱

Caused by: #38098 was opened by shaoxt.

see: more, trace.