public static Bitmap rotateBitmap(Bitmap source, float angle) {
        Matrix matrix = new Matrix();
        matrix.postRotate(angle);
        return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix, true);
    }
Write the given bitmap into the given file. JPEG is used as the compression format with
quality set
to 100.

@param bm   The bitmap.
@param file The file to write the bitmap into.
sample/src/main/java/com/fenctose/imagecropper/BitmapUtils.java