Using migrate module to import to a list_boolean field
See this comment on this issue:
https://www.drupal.org/node/1729996#comment-9511751

"I found a way to import, you must set the "on" and "off" values.

I went to my field in my content type and set the "on" value to 1 and
the "off" value to 0.

In the migration mapping I made a callback function for this field and
convert my true value to 1 and the false value to 0, you could do this
instead creating a new feature.

This way worked perfectly here.

I don't know if it is a really necessary feature."