Motivation

The library is missing the possibility to set the InboxStyle to the notification. This PR adds it.
For details about the InboxStyle: https://developer.android.com/reference/android/app/Notification.InboxStyle.html

Usage

PushNotification.localNotification() and PushNotification.localNotificationSchedule() now accepts a new optional property that is inboxStyle. Following an example:

PushNotification.localNotification({
      inboxStyle: {
        bigContentTitle: "Topic",
        summaryText: "3 messages",
        lines: [
           "John: this is just an example",
           "Brad: of course!",
           "last line, very very very very long that will not wrap but will be truncated by the inbox style"
        ]
      }
    });

Test plan

I added the inboxStyle property to the object passed to PushNotification.localNotification() and PushNotification.localNotificationSchedule() and the notification gets displayed correctly.
If I don't add the inboxStyle, the behavior does not change.

About the code

I needed to copy-paste the code of Arguments.java from react-native repo because, before RN 0.48.0, Arguments was not able to convert lists from ReadableMap to Bundle. I wanted to make this PR compatible with older versions of RN, so I copied the code into the helpers namespace.

I also needed to add a RNUtil class in order to convert a json to WritableMap and vice versa.