Can't select keyboard type during installation

[Maraschin]

USE CASE:
- Several users around the world have local keyboards that are very different from US keyboards but still would like to use English as the default language, or any other combination of language and keyboard. It is important to permit the keyboard to be changed independent of the language selected!

Issue:
- the installation process do not allow the user to select a different keyboard.

Tested versions:
- 18.04 daily (2018-01-01) server - Not working
- 17.10 server - Not working

Steps to Replicate:
- Boot the installation ("pre-installation")
- Select English and language and the appropriate keyboard pressing F3 (in my case was Swedish)
- Select install new Ubuntu server (The "installation")
- select English as language
- try to select another keyboard (like Swedish, Brazilian, etc) during the installation process
  Problem: there is no way to do it in the installation!
  If i try to go back in the menu to set the keyboard, it will not allow me to change it!

Consequences:
- Keyboard is wrongly set
- In case a user uses disk encryption, (s)he may not be able to enter the password after reboot making the all installation useless.
  - Bug #174101 may be a consequence of this problem - in this scenario it is even worse since it will not work even if the combination of language and keyboard suppose to be correct (In case it is something else than English/US)

[Maraschin (carlo-maraschin)]

I tried 17.10.1-server-amd64 today and the problem still there.
I'm not able to select / change the keyboard during the installation!
Which results in the wrong keyboard been set!

I tried bionic-live-server-amd64 daily: 20180220 and I can select the keyboard
but the partition doesn't scan the disks (do not show any of the existing partitions) and it is missing options like encryption and lvm.