fix: Android setPage needs to dispatchEvent on the native side (#41)

Author: ferrannp

android/src/main/java/com/reactnativecommunity/viewpager/ReactViewPager.java

@@ -200,6 +200,7 @@ public boolean onTouchEvent(MotionEvent ev) {
   public void setCurrentItemFromJs(int item, boolean animated) {
     mIsCurrentItemFromJs = true;
     setCurrentItem(item, animated);
+    mEventDispatcher.dispatchEvent(new PageSelectedEvent(getId(), item));
     mIsCurrentItemFromJs = false;
   }