Add opacity animation to fix the issue on Android. Use 'import' syntax to replace 'require'

[jp928]

Add opacity animation to fix the issue on Android. Use 'import' syntax to replace 'require'

[dgladkov]

Looks like this project is abandoned. I've created https://github.com/dgladkov/react-native-flip-view-next that includes a similar fix and more.

My solution uses single Animated.Value for all animations and uses different interpolation function for opacity: instead of linear opacity transition used here it toggles between 0/1 as it reaches half transition (180deg rotation), emulating backfaceVisibility support on Android.