test: Refactor state sync tests to test the public interface

Author: ShuoWangNSL

rs/state_layout/src/state_layout.rs

@@ -56,6 +56,7 @@ pub const SPLIT_MARKER_FILE: &str = "split_from.pbuf";
 pub const SUBNET_QUEUES_FILE: &str = "subnet_queues.pbuf";
 pub const SYSTEM_METADATA_FILE: &str = "system_metadata.pbuf";
 pub const STATS_FILE: &str = "stats.pbuf";
+pub const WASM_FILE: &str = "software.wasm";
 
 /// `ReadOnly` is the access policy used for reading checkpoints. We
 /// don't want to ever modify persisted states.
@@ -1473,7 +1474,7 @@ impl<Permissions: AccessPolicy> CanisterLayout<Permissions> {
     }
 
     pub fn wasm(&self) -> WasmFile<Permissions> {
-        self.canister_root.join("software.wasm").into()
+        self.canister_root.join(WASM_FILE).into()
     }
 
     pub fn canister(

rs/state_manager/src/state_sync.rs

@@ -32,7 +32,7 @@ impl StateSync {
     }
 
     /// Returns requested state as a Chunkable artifact for StateSync.
-    pub fn create_chunkable_state(
+    fn create_chunkable_state(
         &self,
         id: &StateSyncArtifactId,
     ) -> Option<Box<dyn Chunkable<StateSyncMessage> + Send>> {