Add a way to dismiss PopupMenu elements

Summary:
In native Android apps, like the YouTube app, context menus are closed when the device orientation changes.

In React Native apps instead, when having a [PopupMenu](https://developer.android.com/reference/android/widget/PopupMenu.html) open and rotating the device, the PopupMenu is not dismissed and appears in a wrong position on the screen.

This PR exposes a `dismissPopupMenu` method to allow the application to dismiss any open PopupMenu:

```(javascript)
UIManager.dismissPopupMenu()
```
Closes https://github.com/facebook/react-native/pull/15636

Differential Revision: D6837663

Pulled By: hramos

fbshipit-source-id: 7b0f4f04341129ad45c703a50897e17d93651974

ReactAndroid/src/main/java/com/facebook/react/views/toolbar/ReactToolbarManager.java

@@ -33,6 +33,7 @@ import javax.annotation.Nullable;
 public class ReactToolbarManager extends ViewGroupManager<ReactToolbar> {
 
   private static final String REACT_CLASS = "ToolbarAndroid";
+  private static final int COMMAND_DISMISS_POPUP_MENUS = 1;
 
   @Override
   public String getName() {
@@ -157,6 +158,27 @@ public class ReactToolbarManager extends ViewGroupManager<ReactToolbar> {
     return true;
   }
 
+  @Nullable
+  @Override
+  public Map<String, Integer> getCommandsMap() {
+    return MapBuilder.of("dismissPopupMenus", COMMAND_DISMISS_POPUP_MENUS);
+  }
+
+  @Override
+  public void receiveCommand(ReactToolbar view, int commandType, @Nullable ReadableArray args) {
+    switch (commandType) {
+      case COMMAND_DISMISS_POPUP_MENUS: {
+        view.dismissPopupMenus();
+        return;
+      }
+      default:
+        throw new IllegalArgumentException(String.format(
+          "Unsupported command %d received by %s.",
+          commandType,
+          getClass().getSimpleName()));
+    }
+  }
+
   private int[] getDefaultContentInsets(Context context) {
     Resources.Theme theme = context.getTheme();
     TypedArray toolbarStyle = null;