Android: ForegroundServiceDidNotStartInTimeException during rapid foreground/background transitions

## Description

`IVSBackgroundService` crashes with `ForegroundServiceDidNotStartInTimeException` on Android when the app undergoes a rapid foreground/background transition while the IVS player is active.

## Error

```
android.app.RemoteServiceException$ForegroundServiceDidNotStartInTimeException:
Context.startForegroundService() did not then call Service.startForeground():
ServiceRecord{... com.amazonaws.ivs.reactnative.player.IVSBackgroundService}
```

## Root Cause

In `IVSBackgroundService.onStartCommand()`, `startForeground()` is called after `createNotificationChannel()`. Android requires `startForeground()` to be called within 5 seconds of `startForegroundService()`. Under memory pressure or when service startup is delayed by rapid app lifecycle transitions, this window can be exceeded before `onStartCommand()` is ever reached.

## Suggested Fix

Move `createNotificationChannel()` and `startForeground()` to `onCreate()`, which is invoked immediately when the service is created — before `onStartCommand()` — ensuring the foreground declaration happens as early as possible.

```kotlin
override fun onCreate() {
super.onCreate()
createNotificationChannel()
startForeground(NOTIFICATION_ID, buildNotification(true, "", ""))
}

override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
val action = intent?.action

when (action) {
ACTION_STOP -> {
stopForeground(true)
stopSelf()
return START_NOT_STICKY
}
// ...
}

val isPlaying = intent?.getBooleanExtra(EXTRA_IS_PLAYING, true) ?: true
val notificationTitle = intent?.getStringExtra(NOTIFICATION_TITLE) ?: ""
val notificationText = intent?.getStringExtra(NOTIFICATION_TEXT) ?: ""

// Update notification content — channel already created in onCreate()
startForeground(NOTIFICATION_ID, buildNotification(isPlaying, notificationTitle, notificationText))

return START_NOT_STICKY
}
```

## Environment

- `amazon-ivs-react-native-player`: 1.6.0
- Android 12+
- Reproducible under low memory conditions with quick background/foreground transitions (observed with a 37ms pause/resume cycle)

Locate IVSBackgroundService and inspect its onCreate() and onStartCommand() lifecycle. Reproduce rapid foreground/background transitions on Android 12+ under low-memory conditions, then verify the service enters the foreground within the startup window without ForegroundServiceDidNotStartInTimeException and that notification updates still work.

Written by the indexing model from the issue text.