Toolbar at bottom will overlap with images

[chinalwb]

Description: When playing with AREditor full bottom toolbar, the default toolbar is at bottom by default, for this case, when inserting an image the last line will be invisible, covered by the toolbar.

Reproduce steps:

1. Open AREditor full bottom page
2. Type in 111 in the first line and 222 in the 3rd line
3. Focus to the 2nd line
4. Insert an image

Expected Result: The image will be shown between 111 and 222. And both 111 and 222 are visible

Actual Result: 222 is invisible