Add support for RCTText under FlatUIImplementation

Summary: @public Initial version of FlatUIImplementation lacks any primitives support (such as RCTText, RCTImageView or RCTView). This diff add the first part, RCTText (alongside with RCTVirtualText and RCTRawText).

Reviewed By: sriramramani

Differential Revision: D2693348

ReactAndroid/src/main/java/com/facebook/react/flat/VirtualViewManager.java

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.flat;
+
+import android.view.View;
+
+import com.facebook.react.uimanager.ThemedReactContext;
+import com.facebook.react.uimanager.ViewManager;
+
+/**
+ * Base class to ViewManagers that don't map to a View.
+ */
+abstract class VirtualViewManager<C extends FlatShadowNode> extends ViewManager<View, C> {
+  @Override
+  protected View createViewInstance(ThemedReactContext reactContext) {
+    throw new RuntimeException(getName() + " doesn't map to a View");
+  }
+
+  @Override
+  public void updateExtraData(View root, Object extraData) {
+  }
+}