BoxStoreBuilder: prevent modification of model after init.

This is currently not really relevant as model is passed unchecked to the native side and not used for any other purpose. But it may be in the future, so rather be safe than sorry.

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/BoxStoreBuilder.java

@@ -27,6 +27,7 @@
 import java.io.OutputStream;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import javax.annotation.Nonnull;
@@ -107,10 +108,11 @@ private BoxStoreBuilder() {
     /** Called internally from the generated class "MyObjectBox". Check MyObjectBox.builder() to get an instance. */
     @Internal
     public BoxStoreBuilder(byte[] model) {
-        this.model = model;
         if (model == null) {
             throw new IllegalArgumentException("Model may not be null");
         }
+        // Future-proofing: copy to prevent external modification.
+        this.model = Arrays.copyOf(model, model.length);
     }
 
     /**