Adding a background image to WatchFaceKotlin sample

[behrooz55]

Hi, since the render() function inside AnalogWatchCanvasRenderer gets called every second, where and how are we supposed to load and scale an image resource in advance, to use it here (for example, as a background)? in the older version of watch face mechanics (the CanvasWatchFaceService) we do this by overriding the onCreate() inside Engine(). However, I checked the source code of this new implementation (the WatchFaceService), the onCreateEngine() function is already final and the onCreate() is already overridden. So, I couldn't figure out how we are supposed to do this. Also, it seems we have same dilemma with onSurfaceChanged() and other useful functions in older mechanics. I checked all of currently available documents on Android website including following links and didn't find a clue. Did I overlook something?

https://android-developers.googleblog.com/2021/12/develop-watch-faces-with-stable-jetpack.html
https://developer.android.com/reference/kotlin/androidx/wear/watchface/WatchFaceService
https://developer.android.com/training/wearables/watch-faces/service
https://developer.android.com/reference/androidx/wear/watchface/package-summary