This can be a solution, but I don't like it for a few reasons:
1. Uri like 'assets:/dir/subdir/image.png' looks ugly for me.
2. I still need to remove the leading slash in order to pass the path to AssetsManager.open
3. It makes the API inconsistent: http uri requires 2 slashes (e.g., http://google.com), file uri requires 3 slashes (e.g., file:///mnt/sdcard/image.png) and assets uri requires only one slash.