[FLINK-37100][tests] Fix test_netty_shuffle_memory_control.sh in CI f…

…or JDK11+

flink-end-to-end-tests/test-scripts/test_netty_shuffle_memory_control.sh

@@ -36,6 +36,10 @@ set_config_key "taskmanager.network.netty.num-arenas" "1"
 # Limits the direct memory to be one chunk (4M) plus some margins.
 set_config_key "taskmanager.memory.framework.off-heap.size" "7m"
 
+# Enable reflection for Nett4, which reduces its memory footprint on JDK11+,
+# so the allocated memory originally assumed for Netty3 will still be sufficient.
+set_config_key "env.java.opts.taskmanager" "-Dorg.apache.flink.shaded.netty4.io.netty.tryReflectionSetAccessible=true"
+
 # Starts the cluster which includes one TaskManager.
 start_cluster