Enable non-weak ssh ciphers

This commit explicitely enables only those supported
ciphers that weren't considered as 'weak'.

At the moment those are:
* arcfour
* arcfour128
* arcfour256

Change-Id: I39c090e89b7648e901e16ace88c0cd25b4eeef27
Related-Prod: PROD-27242
2 files changed