Add release note and update the outlier detection document

Signed-off-by: ZhouyihaiDing <ddyihai@google.com>

docs/root/intro/arch_overview/upstream/outlier.rst

@@ -145,6 +145,8 @@ Most configuration items, namely
 types of errors, but :ref:`outlier_detection.enforcing_success_rate<envoy_api_field_cluster.OutlierDetection.enforcing_success_rate>` applies
 to externally originated errors only and :ref:`outlier_detection.enforcing_local_origin_success_rate<envoy_api_field_cluster.OutlierDetection.enforcing_local_origin_success_rate>`  applies to locally originated errors only.
 
+For gRPC requests, the outlier detection will use the HTTP status mapped from the [grpc-status](https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#responses) response header.
+
 
 .. _arch_overview_outlier_detection_logging:
 

docs/root/intro/version_history.rst

@@ -33,6 +33,7 @@ Version history
 * listeners: added :ref:`continue_on_listener_filters_timeout <envoy_api_field_Listener.continue_on_listener_filters_timeout>` to configure whether a listener will still create a connection when listener filters time out.
 * listeners: added :ref:`HTTP inspector listener filter <config_listener_filters_http_inspector>`.
 * lua: extended `httpCall()` and `respond()` APIs to accept headers with entry values that can be a string or table of strings.
+* outlier_detector: added support for the grpc-status response header by mapping it to HTTP status. Guarded by envoy.reloadable_features.outlier_detection_support_for_grpc_status which defaults to true.
 * performance: new buffer implementation enabled by default (to disable add "--use-libevent-buffers 1" to the command-line arguments when starting Envoy).
 * performance: stats symbol table implementation (disabled by default; to test it, add "--use-fake-symbol-table 0" to the command-line arguments when starting Envoy).
 * rbac: added support for DNS SAN as :ref:`principal_name <envoy_api_field_config.rbac.v2.Principal.Authenticated.principal_name>`.