Here is one way to easily show a star (yellow in this example) with a star-shaped outline (black in this example):

Box(contentAlignment = Alignment.Center) {
    Icon(
        imageVector = Icons.Default.StarOutline,
        contentDescription = null,
        tint = Color.Black,
        modifier = Modifier.size(24.dp)
     )
     if (isStarred) {
       Icon(
           imageVector = Icons.Default.Star,
            contentDescription = null,
             tint = Color.Yellow,
             modifier = Modifier.size(18.dp)
      )
}