Fixed Build Failure because of new "bitlocker" Enum

[shundhammer]

Bugzilla

https://bugzilla.opensuse.org/show_bug.cgi?id=1199832

Problem

Unit tests fail after a new enum was added in libstorage-ng for bitlocker.

[  122s] Failures:
[  122s] 
[  122s]   1) Y2Storage::EncryptionType#to_human_string for all the possible values of the library returns the translated string
[  122s]      Failure/Error: expect(value.to_human_string).to be_a(::String)
[  122s] 
[  122s]      RuntimeError:
[  122s]        Unhandled encryption type '#<Y2Storage::EncryptionType bitlocker>'
[  122s]      # ./src/lib/y2storage/encryption_type.rb:74:in `to_human_string'
[  122s]      # ./test/y2storage/encryption_type_test.rb:29:in `block (5 levels) in <top (required)>'
[  122s]      # ./test/y2storage/encryption_type_test.rb:28:in `each'
[  122s]      # ./test/y2storage/encryption_type_test.rb:28:in `block (4 levels) in <top (required)>'
[  122s] 
[  122s] Finished in 1 minute 13.75 seconds (files took 3.65 seconds to load)
[  122s] 1070 examples, 1 failure
[  122s] 
[  122s] Failed examples:
[  122s] 
[  122s] rspec ./test/y2storage/encryption_type_test.rb:27 # Y2Storage::EncryptionType#to_human_string for all the possible values of the library returns the translated string

Fix

Added the value to our translatable messages.

[yast-bot]

:heavy_check_mark: Public Jenkins job #439 successfully finished :heavy_check_mark: Created OBS submit request #978727

[coveralls]

Coverage remained the same at 97.821% when pulling 08c9e6d8cf907ae95a80d88184aa170c3e47749f on huha-bitlocker into eb9c0f405064ff8d9fe8930d196f8103d1788337 on master.