remove unused constants, add nil checks, change kays to be same as parameters names for Notification Listener in Android
remove unused constants, add nil checks, change kays to be same as parameters names for Notification Listener in Android

optimizely/objective-c-sdk,relayrides/objective-c-sdk,relayrides/objective-c-sdk,optimizely/objective-c-sdk,optimizely/objective-c-sdk,optimizely/objective-c-sdk,relayrides/objective-c-sdk,relayrides/objective-c-sdk