ReactScrollView should account for overflow: scroll

Summary:
Support for `overflow: visible` was recently added to Android ScrollView.
However, it didn't account for `overflow: scroll` and changed the behavior, causing content to render
when before it would be clipped.

Reviewed By: achen1

Differential Revision: D10036807

fbshipit-source-id: e44a79b18eecbc7d64621f7cf5d800a00a121b13

Author: mcolotto

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java

@@ -195,7 +195,7 @@ protected void onDraw(Canvas canvas) {
     switch (mOverflow) {
       case ViewProps.VISIBLE:
         break;
-      case ViewProps.HIDDEN:
+      default:
         canvas.clipRect(mRect);
         break;
     }

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java

@@ -384,7 +384,7 @@ public void draw(Canvas canvas) {
     switch (mOverflow) {
       case ViewProps.VISIBLE:
         break;
-      case ViewProps.HIDDEN:
+      default:
         canvas.clipRect(mRect);
         break;
     }