fix: Add path prefix presence flag and tests for AppFileInfo

src/main/java/in/dragonbra/javasteam/steam/handlers/steamcloud/AppFileInfo.kt

@@ -11,6 +11,7 @@ class AppFileInfo(response: CCloud_AppFileInfo) {
     val rawFileSize: Int = response.rawFileSize
     val persistState: ECloudStoragePersistState = response.persistState
     val platformsToSync: Int = response.platformsToSync
+    val hasPathPrefixIndex: Boolean = response.hasPathPrefixIndex()
     val pathPrefixIndex: Int = response.pathPrefixIndex
     val machineNameIndex: Int = response.machineNameIndex
 }

src/test/java/in/dragonbra/javasteam/steam/handlers/steamcloud/AppFileInfoTest.java

@@ -0,0 +1,32 @@
+package in.dragonbra.javasteam.steam.handlers.steamcloud;
+
+import in.dragonbra.javasteam.protobufs.steamclient.SteammessagesCloudSteamclient;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class AppFileInfoTest {
+
+    @Test
+    public void hasPathPrefixIndexIsFalseWhenFieldIsMissing() {
+        var response = SteammessagesCloudSteamclient.CCloud_AppFileInfo.newBuilder()
+                .setFileName("save.dat")
+                .build();
+
+        var info = new AppFileInfo(response);
+
+        Assertions.assertFalse(info.getHasPathPrefixIndex());
+    }
+
+    @Test
+    public void hasPathPrefixIndexIsTrueWhenIndexIsZero() {
+        var response = SteammessagesCloudSteamclient.CCloud_AppFileInfo.newBuilder()
+                .setFileName("save.dat")
+                .setPathPrefixIndex(0)
+                .build();
+
+        var info = new AppFileInfo(response);
+
+        Assertions.assertTrue(info.getHasPathPrefixIndex());
+        Assertions.assertEquals(0, info.getPathPrefixIndex());
+    }
+}