backfaceVisibility not documented

[jaygarcia]

Just an FYI, backfaceVisibility doesn't seem to be documented anywhere, but exists for iOS at least.

commander-keen:react-native jgarcia$ grep -r backfaceVisibility .
./Libraries/Components/View/ViewStylePropTypes.js:  backfaceVisibility: ReactPropTypes.oneOf(['visible', 'hidden']),
./Libraries/Image/ImageStylePropTypes.js:  backfaceVisibility: ReactPropTypes.oneOf(['visible', 'hidden']),
./React/Views/RCTViewManager.m:RCT_REMAP_VIEW_PROPERTY(backfaceVisibility, layer.doubleSided, css_backface_visibility_t)
./RNTester/js/TransformExample.js:    backfaceVisibility: 'hidden',

[chirag04]

view style props are not auto generated anymore it seems.

[hramos]

Dupe of #14147