Adds some missing parameters on types

Fix pod installation syntax

Running `pod install Firebase/Messaging` results in `[!] Unknown command: 'Firebase/Messaging'` using Cocoapods v1.3.1.
Also, there was a parse error in `HEADER_SEARCH_PATHS = "$(SRCROOT)/../node_modules/react-native/Libraries/PushNotificationIOS/**""$(SRCROOT)/../node_modules/react-native-fcm/ios";`, I was able to fix it by opening `APPNAME.xcodeproj/project.pbxproj`.

Remove override of createJSModules

Fix typo so 'grant' is spelled correctly

in common error

safe FirebaseInstanceId.getInstance() access.

`FirebaseInstanceId.getInstance()` can throw exceptions. For example if Firebase was not initialized.

Fix sound type definition

Delete instanceId function

Documentation update

Support Android activity aliases

Fix type Listner to Listener

Just return the className. The old code didn't work with activity aliases. For example, when launching with `<activity-alias android:name=".SplashActivity" android:targetActivity=".MainActivity" />`, the old code would try to get the class for `SplashActivity` which threw `ClassNotFoundException`.