[Android] List Block's caret positioning is off when new item at the end

[hypest]

When there are a few empty list items, trying to add a new item at the end will not place the caret correctly.

1. Do a long list, long enough to have a few empty list items here and there
2. Try to add a new item at the end of the list
3. Notice that the caret doesn't land on the new list item but rather, goes "back". The more empty lines from 2., the more chars the caret goes back.

[hypest]

Leaving some context from my investigation so far:

Our current method of setting the selection/caret via JS is not compatible with the way Aztec computes its char positions, especially with content like lists where there are special character in place to implement the list behavior. Those special characters (zero-width-spaces) take up char positions and the JS side doesn't know that. Will need to find a way to reconcile those two models.