Refactor `addStyleImage` function

I get this Platform Exception whenever i try to add an styleImage using the style.addStyleImage() function:
This is the log dump

E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): Failed to handle message
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): java.lang.NullPointerException: Attempt to invoke virtual method 'android.graphics.Bitmap$Config android.graphics.Bitmap.getConfig()' on a null object reference
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at com.mapbox.maps.mapbox_maps.StyleController.addStyleImage(StyleController.kt:611)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at com.mapbox.maps.mapbox_maps.pigeons.StyleManager$Companion.setUp$lambda$93$lambda$92(MapInterfaces.kt:6573)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at com.mapbox.maps.mapbox_maps.pigeons.StyleManager$Companion.$r8$lambda$lRvnrb64UZK1xwpPleLL6Q0pCMo(Unknown Source:0)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at com.mapbox.maps.mapbox_maps.pigeons.StyleManager$Companion$$ExternalSyntheticLambda34.onMessage(Unknown Source:2)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at io.flutter.plugin.common.BasicMessageChannel$IncomingMessageHandler.onMessage(BasicMessageChannel.java:261)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:292)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$io-flutter-embedding-engine-dart-DartMessenger(DartMessenger.java:319)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at io.flutter.embedding.engine.dart.DartMessenger$$ExternalSyntheticLambda0.run(Unknown Source:12)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at android.os.Handler.handleCallback(Handler.java:959)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at android.os.Handler.dispatchMessage(Handler.java:100)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at android.os.Looper.loopOnce(Looper.java:282)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at android.os.Looper.loop(Looper.java:387)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at android.app.ActivityThread.main(ActivityThread.java:9505)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at java.lang.reflect.Method.invoke(Native Method)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:600)
E/BasicMessageChannel#dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0(24833): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1005)
E/flutter (24833): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: PlatformException(channel-error, Unable to establish connection on channel: "dev.flutter.pigeon.mapbox_maps_flutter.StyleManager.addStyleImage.0"., null, null)
E/flutter (24833): #0      StyleManager.addStyleImage (package:mapbox_maps_flutter/src/pigeons/map_interfaces.dart:7142:7)```

Start by reproducing the addStyleImage failure and inspect StyleController.kt:611, then trace the call from package:mapbox_maps_flutter/src/pigeons/map_interfaces.dart:7142. Determine why the Android handler receives a null Bitmap and verify that valid style images no longer produce the reported PlatformException.