Android Breaks When initialPage Index > 10

Related to issue #9
Affected version: v2.1.5
Affects Android Only
Work around: downgraded to v2.1.4

Issue Summary

With v2.1.5 installed, tapping any thumbnail greater than 10 causes unexpected behavior ranging from the wrong image being displayed to loss of swipe and pinch-to-zoom functionality.

Issue Details

1. When tapping thumbnails on a Flatlist Grid when index <= 10, everything works as expected. The correct image appears full screen in the gallery, pinch-to-zoom works, swiping works. All is good.
2. When index === 11, the 10th image flashes but the 11th is eventually shown. Both pinch-to-zoom and swiping work as expected.
3. When index ===12, the 10th image flashes, 11th image is shown. Both pinch-to-zoom and slider sometimes work, sometimes not. It's inconsistent. When working, the 12th image immediately appears on swipe initiation (without animation).
4. When index >=13, the 10th image flashes, 11th image is shown. Neither pinch-to-zoom nor slider work (ever!).

Here's a video demonstrating the issue...
http://recordit.co/pSRuvmcX04

More Info which may or may not be helpful

While troubleshooting this, I verified that the offsetX calculation is correct in react-native-image-gallery#225

• Docs: FlatList.scrollToOffset()
• Docs: VirtualizedList.scrollToOffset()
• I found this issue in another app as well. Download "Kitten Tricks". Then go to Social > User Profile V1 (2 or 3 work as well) > then under the thumbnails, tapping on any thumbnail thumbnailIndex <= 10 results in the correct image being enlarged. thumbnailIndex > 10 results in the 10th image being enlarged.

Start with src/libraries/ViewPager/index.js, including the offsetX calculation referenced near line 225, and reproduce the Android behavior from a FlatList grid using thumbnail indices 10, 11, 12, and 13 or higher. Compare the behavior between v2.1.4 and v2.1.5; done means every thumbnail opens the correct image with reliable swiping and pinch-to-zoom.