[ci skip] Fix `before_filter` -> `before_action`

guides/source/api_app.md

@@ -367,7 +367,7 @@ controller modules by default:
   methods returning `ActionDispatch::Request` and `ActionDispatch::Response`
   objects.
 - `ActionController::DataStreaming`: Support for `send_file` and `send_data`.
-- `AbstractController::Callbacks`: Support for `before_filter` and friends.
+- `AbstractController::Callbacks`: Support for `before_action` and friends.
 - `ActionController::Instrumentation`: Support for the instrumentation
   hooks defined by Action Controller (see [the instrumentation
   guide](active_support_instrumentation.html#action-controller)).