@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR1)
    public static void setAlpha(Bitmap toTransform, Bitmap outBitmap) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1 && outBitmap != null) {
            outBitmap.setHasAlpha(toTransform.hasAlpha());
        }
    }
Sets the alpha of the Bitmap we're going to re-use to the alpha of the Bitmap we're going to transform. This
keeps {@link Bitmap#hasAlpha()}} consistent before and after the transformation for
transformations that don't add or remove transparent pixels.

@param toTransform The {@link Bitmap} that will be transformed.
@param outBitmap The {@link Bitmap} that will be returned from the transformation.
core/src/main/java/com/bumptech/glide/load/resource/bitmap/TransformationUtils.java