Not every key in the firebase's {android/ios}.notification object is supported in "additionalData" object

[stagefright5]

Expected Behaviour

Should preserve all the "unsupported" keys in the "additionalData" object

Actual Behaviour

Does not preserve all the key-value pairs in Androidref and iOSref notification objects

For example: image, sticky, visibility, notification_count

Reproduce Scenario (including but not limited to)

Send a notification through FCM to an app that is using this plugin and log the argument of .on('notification')'s callback

Steps to Reproduce

1. Initialize the android and iOS notifications
2. Listen for "notification" event
3. Log the argument of the event listener's callback

Platform and Version (eg. Android 5.0 or iOS 9.2.1)

Android 9

(Android) What device vendor (e.g. Samsung, HTC, Sony...)

Samsung

Cordova CLI version and cordova platform version

cordova --version   # 9.0.0
cordova platform version android     # 7.14.0

Plugin version

cordova plugin version | grep phonegap-plugin-push  # 2.2.3

Sample Push Data Payload

{
    title: title,
    body: body,
    icon: icon,
    color: pinkColor,
    // "sound": string,
    tag: randomtag,
    // "click_action": string,
    // "body_loc_key": string,
    // "body_loc_args": [
    //   string
    // ],
    // "title_loc_key": string,
    // "title_loc_args": [
    //   string
    // ],
    // "channel_id": string,
    // "ticker": string,
    sticky: sticky,
    // "event_time": string,
    // "local_only": boolean,
    // "notification_priority": ,
    // "default_sound": boolean,
    default_vibrate_timings: default_vibrate_timings,
    // "default_light_settings": boolean,
    // "vibrate_timings": [
    //   string
    // ],
    visibility: visibility,
    notification_count: count,
    // "light_settings": {
    //   object(LightSettings)
    // },
    image: image
}

Sample Code that illustrates the problem

// After registration
push.on("notification", (function(data) {
                        console.log('[_initializeAndroidIOSNotifications] on push "notification":', data.additionalData);
});

Logs taken while reproducing problem

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