Fix ASAN error in ext_authz tests (envoyproxy#31967)

Signed-off-by: Yan Avlasov <yavlasov@google.com>

source/extensions/filters/http/ext_authz/ext_authz.h

@@ -388,7 +388,7 @@ class Filter : public Logger::Loggable<Logger::Id::ext_authz>,
 
   // This is used to hold the final configs after we merge them with per-route configs.
   bool allow_partial_message_{};
-  uint32_t max_request_bytes_;
+  uint32_t max_request_bytes_{};
 
   // Used to identify if the callback to onComplete() is synchronous (on the stack) or asynchronous.
   bool initiating_call_{};