Update OtpVerify.h to prevent new NativeEventEmitter() warnings

[adgang]

This addresses #74 in ios.

Before:
We see in logs(if LogBox warnings are disabled):

 WARN  `new NativeEventEmitter()` was called with a non-null argument without the required `addListener` method.
 WARN  `new NativeEventEmitter()` was called with a non-null argument without the required `removeListeners` method.

After:
logs are clean.

[adgang]

Based on: https://reactnative.dev/docs/native-modules-ios#sending-events-to-javascript

Potential fix for android as per:
react/react-native#32051

is(sample):
invertase/react-native-firebase#5616

[johelder]

any update?

[tomerh2001]

See my #138