[ReactNative] Register assets with AssetRegistry

Libraries/Image/AssetRegistry.js

@@ -0,0 +1,20 @@
+/**
+ * Copyright 2004-present Facebook. All Rights Reserved.
+ *
+ * @providesModule AssetRegistry
+ */
+'use strict';
+
+var assets = [];
+
+function registerAsset(asset) {
+  // `push` returns new array length, so the first asset will
+  // get id 1 (not 0) to make the value truthy
+  return assets.push(asset);
+}
+
+function getAssetByID(assetId) {
+  return assets[assetId - 1];
+}
+
+module.exports = { registerAsset, getAssetByID };