When image height bigger than textHeight，the image can not be in center

[shiqos]

From CustomImageSpan.java

@public void draw() {
       ......
        if (drawableHeight > textHeight) {
            super.draw(canvas, text, start, end, x, top, y, bottom, paint);
            return;
        }
       .....

From code we can get that if Image height bigger than textHeight and it will goto super.draw() and the SpecialGravityEnum will no effect