Allow zIndex to useNativeDriver (#27418)

Summary:
STYLES_WHITELIST
+zIndex
Pull Request resolved: #27418

Test Plan: Working on sim and device.

Differential Revision: D19644753

Pulled By: shergin

fbshipit-source-id: 9a3516f65de7011f7e91587e62153e083504d283

Libraries/Animated/src/NativeAnimatedHelper.js

@@ -172,6 +172,7 @@ const STYLES_WHITELIST = {
  borderTopRightRadius: true,
  borderTopStartRadius: true,
  elevation: true,
+ zIndex: true,
  /* ios styles */
  shadowOpacity: true,
  shadowRadius: true,