Add scrollWithoutAnimationTo to Android

Summary: `ScrollView.scrollWithoutAnimationTo` is supported on iOS but not Android. This is an existing API, and this diff adds Android support.

Closes https://github.com/facebook/react-native/pull/2695

Reviewed By: @​svcscm

Differential Revision: D2452630

Pulled By: @mkonicek

Libraries/Components/ScrollResponder.js

@@ -366,6 +366,26 @@ var ScrollResponderMixin = {
     }
   },
 
+  /**
+   * Like `scrollResponderScrollTo` but immediately scrolls to the given
+   * position
+   */
+  scrollResponderScrollWithouthAnimationTo: function(offsetX: number, offsetY: number) {
+    if (Platform.OS === 'android') {
+      RCTUIManager.dispatchViewManagerCommand(
+        React.findNodeHandle(this),
+        RCTUIManager.RCTScrollView.Commands.scrollWithoutAnimationTo,
+        [offsetX, offsetY],
+      );
+    } else {
+      RCTUIManager.scrollWithoutAnimationTo(
+        React.findNodeHandle(this),
+        offsetX,
+        offsetY
+      );
+    }
+  },
+
   /**
    * A helper function to zoom to a specific rect in the scrollview.
    * @param {object} rect Should have shape {x, y, width, height}