runtime-rs: CreateContainerRequest has Default

We can just use it to initialize the default fields.

Signed-off-by: Peng Tao <bergwolf@hyper.sh>

src/runtime-rs/crates/runtimes/virt_container/src/container_manager/container.rs

@@ -143,13 +143,10 @@ impl Container {
         // create container
         let r = agent::CreateContainerRequest {
             process_id: agent::ContainerProcessID::new(&config.container_id, ""),
-            string_user: None,
-            devices: vec![],
             storages,
             oci: Some(spec),
-            guest_hooks: None,
             sandbox_pidns,
-            rootfs_mounts: vec![],
+            ..Default::default()
         };
 
         self.agent