fix incorrectly serialized model for delete (#1131)

Author: raphkim

aws-datastore/src/main/java/com/amplifyframework/datastore/storage/sqlite/SQLiteStorageAdapter.java

@@ -498,7 +498,7 @@ public <T extends Model> void delete(
                     ModelSchema schema = modelSchemaRegistry.getModelSchemaForModelInstance(cascadedModel);
                     itemChangeSubject.onNext(StorageItemChange.builder()
                         .item(cascadedModel)
-                        .patchItem(SerializedModel.create(cascadedModel, modelSchema))
+                        .patchItem(SerializedModel.create(cascadedModel, schema))
                         .modelSchema(schema)
                         .type(StorageItemChange.Type.DELETE)
                         .predicate(QueryPredicates.all())