[FIX] input_choice: get length of list copy

If the parameters have been zipped with Python 3 the options are at
first an zip object where len() doesn't work. So as long as list() does
work on the options it's fine and we use that length then.

Change-Id: Ica95745c2bcc0490e93ae35510e95d5073f8cb94
Merge "[FIX] input_choice: get length of list copy"