fix(keyboard): overflow: visible on scroll view when keyboard is open

When using JS scrolling, prevents the web view from automatically
scrolling inputs into view when they are either scrolled under the
keyboard or already below the keyboard and typed into.

test/unit/views/scrollView.unit.js

@@ -73,6 +73,7 @@ describe('Scroll View', function() {
     expect(sv.resize).toHaveBeenCalled();
     expect(sv.isShrunkForKeyboard).toBe(true);
     expect(sc.style.height).toEqual("248px");
+    expect(sc.style.overflow).toEqual("visible");
 
     ionic.trigger('scrollChildIntoView', details, true);
     //already shrunk, so shouldn't resize again