chore: #796 に対するJavaのテストを追加 (#797)

* chore: #796 に対するJavaのテストを追加

* テスト名を変更

crates/voicevox_core_java_api/lib/src/test/java/jp/hiroshiba/voicevoxcore/VoiceModelTest.java

@@ -0,0 +1,36 @@
+package jp.hiroshiba.voicevoxcore;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.google.gson.Gson;
+import com.google.gson.annotations.Expose;
+import com.google.gson.annotations.SerializedName;
+import jakarta.annotation.Nonnull;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+class VoiceModelTest extends TestUtils {
+  @Test
+  void idShouldBePreservedAsIs() throws IOException {
+    UUID expected = UUID.fromString(Manifest.readJson().id);
+    UUID actual = loadModel().id;
+    assertEquals(expected, actual);
+  }
+
+  private static class Manifest {
+    @SerializedName("id")
+    @Expose
+    @Nonnull
+    String id;
+
+    static Manifest readJson() throws IOException {
+      Path path = new File("../../../model/sample.vvm/manifest.json").toPath();
+      String json = new String(Files.readAllBytes(path));
+      return new Gson().fromJson(json, Manifest.class);
+    }
+  }
+}