Summary:
This is an updated version of #22579 which uses compile conditionals to prevent `use of undeclared identifier` errors when compiling on older versions of Xcode.
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Currently the only `textContentType` values that work are: `username`, `password`, `location`, `name` and `nickname`. This is due to the strings provided by React Native not matching up with the underlying string constants used in iOS (with the exception of the aforementioned types). Issue #22578 has more detail examples/explanation.
Pull Request resolved: https://github.com/facebook/react-native/pull/22611
Differential Revision: D13460949
Pulled By: cpojer
fbshipit-source-id: e6d1108422b850ebc3aea05693ed05118b77b5de