compression: add per-route remove_accept_encoding_header (#29877)

* compression: add per-route remove_accept_encoding_header

The use case: envoy is handling compression for all routes by default,
but some routes _may_ be able to handle compression better than
envoy (e.g. by serving precompressed assets), or they may not, in which
case envoy should still compress. The existing per-route compression
configuration, which only consists of "entirely disabling compression",
is not acceptable for this use case.

Signed-off-by: Ian Kerins <git@isk.haus>

Mirrored from https://github.com/envoyproxy/envoy @ 24efd20cfc69f664cb1c94e83537e940fcbb1e2d

envoy/extensions/filters/http/compressor/v3/compressor.proto

@@ -132,8 +132,11 @@ message Compressor {
 }
 
 // Per-route overrides of ``ResponseDirectionConfig``. Anything added here should be optional,
-// to allow overriding arbitrary subsets of configuration. Omitted fields must have no affect.
+// to allow overriding arbitrary subsets of configuration. Omitted fields must have no effect.
 message ResponseDirectionOverrides {
+  // If set, overrides the filter-level
+  // :ref:`remove_accept_encoding_header<envoy_v3_api_field_extensions.filters.http.compressor.v3.Compressor.ResponseDirectionConfig.remove_accept_encoding_header>`.
+  google.protobuf.BoolValue remove_accept_encoding_header = 1;
 }
 
 // Per-route overrides. As per-route overrides are needed, they should be